mtd: ensure MTD/the raw NAND core are compiled when there is a NAND flash

Both symbols must be enabled when there is a raw NAND driver
selected. Also enable them when CONFIG_CMD_NAND is selected to avoid
breaking things when we'll further rework the MTD dependency
description.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
[trini: Rebase and migrate a few more boards here]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/am335x_guardian_defconfig b/configs/am335x_guardian_defconfig
index 2d6204b..5526e80 100644
--- a/configs/am335x_guardian_defconfig
+++ b/configs/am335x_guardian_defconfig
@@ -61,6 +61,7 @@
 CONFIG_MISC=y
 # CONFIG_MMC is not set
 CONFIG_DM_MTD=y
+CONFIG_MTD=y
 CONFIG_MTD_RAW_NAND=y
 CONFIG_SYS_NAND_U_BOOT_LOCATIONS=y
 CONFIG_SYS_NAND_U_BOOT_OFFS=0x100000