mtd: rename CONFIG_NAND -> CONFIG_MTD_RAW_NAND

Add more clarity by changing the Kconfig entry name.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
[trini: Re-run migration, update a few more cases]
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
diff --git a/configs/platinum_picon_defconfig b/configs/platinum_picon_defconfig
index 58edba0..450b772 100644
--- a/configs/platinum_picon_defconfig
+++ b/configs/platinum_picon_defconfig
@@ -54,7 +54,7 @@
 CONFIG_ENV_OFFSET_REDUND=0x1080000
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_FSL_USDHC=y
-CONFIG_NAND=y
+CONFIG_MTD_RAW_NAND=y
 CONFIG_NAND_MXS=y
 CONFIG_PHYLIB=y
 CONFIG_MII=y