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>
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 6c71f62..95b8d2b 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -55,7 +55,7 @@
 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.