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/mx7dsabresd_qspi_defconfig b/configs/mx7dsabresd_qspi_defconfig
index c317453..865ce30 100644
--- a/configs/mx7dsabresd_qspi_defconfig
+++ b/configs/mx7dsabresd_qspi_defconfig
@@ -54,6 +54,7 @@
 CONFIG_MMC_UHS_SUPPORT=y
 CONFIG_MMC_HS200_SUPPORT=y
 CONFIG_FSL_USDHC=y
+CONFIG_MTD=y
 CONFIG_DM_SPI_FLASH=y
 CONFIG_SF_DEFAULT_MODE=0
 CONFIG_SF_DEFAULT_SPEED=40000000