mx6: Add board mx6memcal for use in validating DDR

This is a virtual "board" that uses configuration files and
Kconfig to define the memory layout used by a real board during
the board bring-up process.

It generates an SPL image that can be loaded using imx_usb or
SB_LOADER.exe.

When run, it will generate a set of calibration constants for
use in either or both a DCD configuration file for boards that
use u-boot.imx or struct mx6_mmdc_calibration for boards that
boot via SPL.

In essence, it is a configurable, open-source variant of the
Freescale ddr-stress tool.

	https://community.nxp.com/docs/DOC-105652

File mx6memcal_defconfig configures the board for use with
mx6sabresd or mx6qsabreauto.

Signed-off-by: Eric Nelson <eric@nelint.com>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
diff --git a/board/freescale/mx6memcal/mx6memcal.c b/board/freescale/mx6memcal/mx6memcal.c
new file mode 100644
index 0000000..afea0fb
--- /dev/null
+++ b/board/freescale/mx6memcal/mx6memcal.c
@@ -0,0 +1,32 @@
+/*
+ * mx6memcal board support - provides a minimal, UART-only
+ * U-Boot that's capable of running a memory test.
+ *
+ * Copyright (C) 2016 Nelson Integration, LLC
+ * Author: Eric Nelson <eric@nelint.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/arch/sys_proto.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int board_init(void)
+{
+	return 0;
+}
+
+int checkboard(void)
+{
+	puts("Board: mx6memcal\n");
+	return 0;
+}
+
+int dram_init(void)
+{
+	gd->ram_size = imx_ddr_size();
+	return 0;
+}
+