imx:mx6sxsabresd add qspi support

Configure the pad setting and enable qspi clock to support qspi
flashes access.

Add QSPI related macro in configuration header file.

Note:
mx6sxsabresd Revb board, 32M flash is used, but in header file,
CONFIG_SPI_FLASH_BAR is not defined, and we still use SZ_16M.
The LUT initialization qspi_set_lut function uses 32BIT addr,
however CONFIG_SPI_FLASH_BAR  and 24BIT addr should be used to
access bigger than 16MB size flash, and BRRD/BRWR should also
be supported. Future patches will fix this.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
diff --git a/include/configs/mx6sxsabresd.h b/include/configs/mx6sxsabresd.h
index 61a7a7a..469d250 100644
--- a/include/configs/mx6sxsabresd.h
+++ b/include/configs/mx6sxsabresd.h
@@ -235,6 +235,18 @@
 /* FLASH and environment organization */
 #define CONFIG_SYS_NO_FLASH
 
+#define CONFIG_FSL_QSPI
+
+#ifdef CONFIG_FSL_QSPI
+#define CONFIG_CMD_SF
+#define CONFIG_SPI_FLASH
+#define CONFIG_SPI_FLASH_SPANSION
+#define CONFIG_SPI_FLASH_STMICRO
+#define CONFIG_SYS_FSL_QSPI_LE
+#define FSL_QSPI_FLASH_SIZE		SZ_16M
+#define FSL_QSPI_FLASH_NUM		2
+#endif
+
 #define CONFIG_ENV_OFFSET		(6 * SZ_64K)
 #define CONFIG_ENV_SIZE			SZ_8K
 #define CONFIG_ENV_IS_IN_MMC