mtd: nand: Kconfig: Add NAND_MXS entry

Added kconfig for NAND_MXS driver.

Cc: Scott Wood <oss@buserror.net>
Cc: Simon Glass <sjg@chromium.org>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Matteo Lisi <matteo.lisi@engicam.com>
Cc: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 5ce7d6d..df154bf 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -80,6 +80,13 @@
 	  controller. This uses the hardware ECC for read and
 	  write operations.
 
+config NAND_MXS
+	bool "MXS NAND support"
+	depends on MX6
+	help
+	  This enables NAND driver for the NAND flash controller on the
+	  MXS processors.
+
 comment "Generic NAND options"
 
 # Enhance depends when converting drivers to Kconfig which use this config