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/silk_defconfig b/configs/silk_defconfig
index 015f2d1..ea17cc3 100644
--- a/configs/silk_defconfig
+++ b/configs/silk_defconfig
@@ -68,8 +68,8 @@
 CONFIG_DM_MMC=y
 CONFIG_SH_MMCIF=y
 CONFIG_RENESAS_SDHI=y
+CONFIG_MTD=y
 CONFIG_DM_MTD=y
-CONFIG_MTD_DEVICE=y
 CONFIG_DM_SPI_FLASH=y
 CONFIG_SPI_FLASH_SPANSION=y
 CONFIG_SPI_FLASH_MTD=y