Convert CONFIG_SYS_NAND_4BIT_HW_ECC_OOBFIRST to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_NAND_4BIT_HW_ECC_OOBFIRST

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
index a7196d5..da2c579 100644
--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -136,6 +136,10 @@
 	  Enable this driver for NAND flash controllers available in TI Davinci
 	  and Keystone2 platforms
 
+config SYS_NAND_4BIT_HW_ECC_OOBFIRST
+	bool "Use 4-bit HW ECC with OOB at the front"
+	depends on NAND_DAVINCI
+
 config KEYSTONE_RBL_NAND
 	depends on ARCH_KEYSTONE
 	def_bool y