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/socfpga_is1_defconfig b/configs/socfpga_is1_defconfig
index 3374823..908a5cb 100644
--- a/configs/socfpga_is1_defconfig
+++ b/configs/socfpga_is1_defconfig
@@ -43,7 +43,7 @@
 CONFIG_DM_I2C=y
 CONFIG_SYS_I2C_DW=y
 # CONFIG_MMC is not set
-CONFIG_MTD_DEVICE=y
+CONFIG_MTD=y
 CONFIG_SPI_FLASH_STMICRO=y
 CONFIG_SPI_FLASH_MTD=y
 CONFIG_PHY_MICREL=y