mtd: denali: make MTD_NAND_DENALI_DT dependent on OF

The build passes even if CONFIG_OF is undefined, but it makes sense
to let it depend on OF.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/nand/Kconfig

@@ -55,7 +55,7 @@ config MTD_NAND_DENALI_PCI
 config MTD_NAND_DENALI_DT
 	tristate "Support Denali NAND controller as a DT device"
 	select MTD_NAND_DENALI
-	depends on HAS_DMA && HAVE_CLK
+	depends on HAS_DMA && HAVE_CLK && OF
 	help
 	  Enable the driver for NAND flash on platforms using a Denali NAND
 	  controller as a DT device.