mtd: nand: denali_dt: add a DT driver

A patch for NAND uclass support was proposed about half a year ago:
https://patchwork.ozlabs.org/patch/722282/

It was not merged and I do not see on-going work for this.

Without DM-based probing, we need to set up pinctrl etc. in an ad-hoc
way and give lots of crappy CONFIG options for base addresses and
properties, which are supposed to be specified by DT.  This is painful.

This commit just provides a probe hook to retrieve "reg" from DT and
allocate private data in a DM manner.  This DT driver is not essentially
a NAND driver, in fact it is (ab)using UCLASS_MISC.  Once UCLASS_NAND is
supported, it would be possible to migrate to it.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 71d678f..85b26d6 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -16,6 +16,13 @@
 	help
 	  Enable support for the Denali NAND controller.
 
+config NAND_DENALI_DT
+	bool "Support Denali NAND controller as a DT device"
+	depends on NAND_DENALI && OF_CONTROL && DM
+	help
+	  Enable the driver for NAND flash on platforms using a Denali NAND
+	  controller as a DT device.
+
 config SYS_NAND_DENALI_64BIT
 	bool "Use 64-bit variant of Denali NAND controller"
 	depends on NAND_DENALI