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/stmark2_defconfig b/configs/stmark2_defconfig
index 4c5de08..036ff70 100644
--- a/configs/stmark2_defconfig
+++ b/configs/stmark2_defconfig
@@ -27,7 +27,7 @@
 CONFIG_ENV_SPI_CS=1
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 # CONFIG_NET is not set
-CONFIG_MTD_DEVICE=y
+CONFIG_MTD=y
 CONFIG_DM_SPI_FLASH=y
 CONFIG_SF_DEFAULT_SPEED=50000000
 CONFIG_SPI_FLASH_ISSI=y