ARM: i.MX: provide declaration for board_spi_cs_gpio

Provide a public declaration of the board_spi_cs_gpio()
callback for i.MX SPI chip selects to prevent the warning
"Should it be static?" when compiling with "make C=1".

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
diff --git a/arch/arm/include/asm/imx-common/spi.h b/arch/arm/include/asm/imx-common/spi.h
new file mode 100644
index 0000000..1d4473a
--- /dev/null
+++ b/arch/arm/include/asm/imx-common/spi.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __MXC_SPI_H_
+#define __MXC_SPI_H_
+
+/*
+ * Board-level chip-select callback
+ * Should return GPIO # to be used for chip-select
+ */
+
+int board_spi_cs_gpio(unsigned bus, unsigned cs);
+
+#endif
diff --git a/board/boundary/nitrogen6x/nitrogen6x.c b/board/boundary/nitrogen6x/nitrogen6x.c
index 951b820..fcd4d82 100644
--- a/board/boundary/nitrogen6x/nitrogen6x.c
+++ b/board/boundary/nitrogen6x/nitrogen6x.c
@@ -18,6 +18,7 @@
 #include <asm/imx-common/iomux-v3.h>
 #include <asm/imx-common/mxc_i2c.h>
 #include <asm/imx-common/sata.h>
+#include <asm/imx-common/spi.h>
 #include <asm/imx-common/boot_mode.h>
 #include <asm/imx-common/video.h>
 #include <mmc.h>
diff --git a/board/compulab/cm_fx6/common.c b/board/compulab/cm_fx6/common.c
index 1f39679..59c9d1a 100644
--- a/board/compulab/cm_fx6/common.c
+++ b/board/compulab/cm_fx6/common.c
@@ -11,6 +11,7 @@
 #include <common.h>
 #include <asm/arch/sys_proto.h>
 #include <asm/gpio.h>
+#include <asm/imx-common/spi.h>
 #include <fsl_esdhc.h>
 #include "common.h"
 
diff --git a/board/embest/mx6boards/mx6boards.c b/board/embest/mx6boards/mx6boards.c
index a725f15..02fb3fa 100644
--- a/board/embest/mx6boards/mx6boards.c
+++ b/board/embest/mx6boards/mx6boards.c
@@ -23,6 +23,7 @@
 #include <asm/imx-common/iomux-v3.h>
 #include <asm/imx-common/boot_mode.h>
 #include <asm/imx-common/mxc_i2c.h>
+#include <asm/imx-common/spi.h>
 #include <asm/imx-common/video.h>
 #include <i2c.h>
 #include <mmc.h>
diff --git a/board/freescale/mx6qsabreauto/mx6qsabreauto.c b/board/freescale/mx6qsabreauto/mx6qsabreauto.c
index 1cb7561..9ab502f 100644
--- a/board/freescale/mx6qsabreauto/mx6qsabreauto.c
+++ b/board/freescale/mx6qsabreauto/mx6qsabreauto.c
@@ -17,6 +17,7 @@
 #include <asm/imx-common/iomux-v3.h>
 #include <asm/imx-common/mxc_i2c.h>
 #include <asm/imx-common/boot_mode.h>
+#include <asm/imx-common/spi.h>
 #include <mmc.h>
 #include <fsl_esdhc.h>
 #include <miiphy.h>
diff --git a/board/freescale/mx6slevk/mx6slevk.c b/board/freescale/mx6slevk/mx6slevk.c
index a0832f4..a500133 100644
--- a/board/freescale/mx6slevk/mx6slevk.c
+++ b/board/freescale/mx6slevk/mx6slevk.c
@@ -13,6 +13,7 @@
 #include <asm/arch/sys_proto.h>
 #include <asm/gpio.h>
 #include <asm/imx-common/iomux-v3.h>
+#include <asm/imx-common/spi.h>
 #include <asm/io.h>
 #include <linux/sizes.h>
 #include <common.h>
diff --git a/board/gateworks/gw_ventana/gw_ventana.c b/board/gateworks/gw_ventana/gw_ventana.c
index 1038d9d..df491a8 100644
--- a/board/gateworks/gw_ventana/gw_ventana.c
+++ b/board/gateworks/gw_ventana/gw_ventana.c
@@ -20,6 +20,7 @@
 #include <asm/imx-common/mxc_i2c.h>
 #include <asm/imx-common/boot_mode.h>
 #include <asm/imx-common/sata.h>
+#include <asm/imx-common/spi.h>
 #include <asm/imx-common/video.h>
 #include <jffs2/load_kernel.h>
 #include <hwconfig.h>
diff --git a/board/genesi/mx51_efikamx/efikamx.c b/board/genesi/mx51_efikamx/efikamx.c
index 137e4ed..6ba55cd 100644
--- a/board/genesi/mx51_efikamx/efikamx.c
+++ b/board/genesi/mx51_efikamx/efikamx.c
@@ -14,6 +14,7 @@
 #include <asm/arch/sys_proto.h>
 #include <asm/arch/crm_regs.h>
 #include <asm/arch/clock.h>
+#include <asm/imx-common/spi.h>
 #include <i2c.h>
 #include <mmc.h>
 #include <fsl_esdhc.h>
diff --git a/board/ttcontrol/vision2/vision2.c b/board/ttcontrol/vision2/vision2.c
index b5249e7..247991d 100644
--- a/board/ttcontrol/vision2/vision2.c
+++ b/board/ttcontrol/vision2/vision2.c
@@ -15,6 +15,7 @@
 #include <asm/arch/iomux-mx51.h>
 #include <asm/gpio.h>
 #include <asm/arch/sys_proto.h>
+#include <asm/imx-common/spi.h>
 #include <i2c.h>
 #include <mmc.h>
 #include <power/pmic.h>
diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
index 026f680..be10269 100644
--- a/drivers/spi/mxc_spi.c
+++ b/drivers/spi/mxc_spi.c
@@ -12,6 +12,7 @@
 #include <asm/gpio.h>
 #include <asm/arch/imx-regs.h>
 #include <asm/arch/clock.h>
+#include <asm/imx-common/spi.h>
 
 #ifdef CONFIG_MX27
 /* i.MX27 has a completely wrong register layout and register definitions in the