ARM: omap2plus_defconfig: Fix errors with NAND BCH

Looks like we need to have BCH enabled to get NAND
working and to avoid getting:

nand: error: CONFIG_MTD_NAND_ECC_BCH not enabled
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/configs/omap2plus_defconfig

@@ -111,6 +111,7 @@ CONFIG_MTD_OOPS=y
 CONFIG_MTD_CFI=y
 CONFIG_MTD_CFI_INTELEXT=y
 CONFIG_MTD_NAND=y
+CONFIG_MTD_NAND_ECC_BCH=y
 CONFIG_MTD_NAND_OMAP2=y
 CONFIG_MTD_ONENAND=y
 CONFIG_MTD_ONENAND_VERIFY_WRITE=y