mtd: rename CONFIG_MTD_DEVICE -> CONFIG_MTD

Like in Linux, just use CONFIG_MTD to compile the MTD stack.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
diff --git a/configs/kmtepr2_defconfig b/configs/kmtepr2_defconfig
index d84da2d..3605a55 100644
--- a/configs/kmtepr2_defconfig
+++ b/configs/kmtepr2_defconfig
@@ -168,8 +168,8 @@
 CONFIG_BOOTCOUNT_LIMIT=y
 CONFIG_BOOTCOUNT_BOOTLIMIT=3
 # CONFIG_MMC is not set
+CONFIG_MTD=y
 CONFIG_MTD_NOR_FLASH=y
-CONFIG_MTD_DEVICE=y
 CONFIG_FLASH_CFI_DRIVER=y
 CONFIG_SYS_FLASH_USE_BUFFER_WRITE=y
 CONFIG_FLASH_CFI_MTD=y