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/display5_factory_defconfig b/configs/display5_factory_defconfig
index 65214bb..676dee8 100644
--- a/configs/display5_factory_defconfig
+++ b/configs/display5_factory_defconfig
@@ -94,7 +94,7 @@
 CONFIG_SYS_I2C_EEPROM_ADDR_LEN=2
 CONFIG_SUPPORT_EMMC_BOOT=y
 CONFIG_FSL_USDHC=y
-CONFIG_MTD_DEVICE=y
+CONFIG_MTD=y
 CONFIG_DM_SPI_FLASH=y
 CONFIG_SF_DEFAULT_BUS=1
 CONFIG_SF_DEFAULT_MODE=0