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/smdkv310_defconfig b/configs/smdkv310_defconfig
index 95d83cf..4e1698b 100644
--- a/configs/smdkv310_defconfig
+++ b/configs/smdkv310_defconfig
@@ -25,6 +25,7 @@
 CONFIG_MMC_SDHCI=y
 CONFIG_MMC_SDHCI_SDMA=y
 CONFIG_MMC_SDHCI_S5P=y
+CONFIG_MTD=y
 CONFIG_SMC911X=y
 CONFIG_SMC911X_BASE=0x5000000
 CONFIG_USB=y