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/mx53cx9020_defconfig b/configs/mx53cx9020_defconfig
index 3e16f45..112c301 100644
--- a/configs/mx53cx9020_defconfig
+++ b/configs/mx53cx9020_defconfig
@@ -31,6 +31,7 @@
 CONFIG_DM_GPIO=y
 CONFIG_DM_MMC=y
 CONFIG_FSL_ESDHC_IMX=y
+CONFIG_MTD=y
 CONFIG_FEC_MXC=y
 CONFIG_MII=y
 CONFIG_PINCTRL=y