mtd: rawnand: davinci: Allow selection of this driver when COMPILE_TEST=y

It just makes NAND maintainers' life easier by allowing them to
compile-test this driver without having ARCH_DAVINCI or ARCH_KEYSTONE
enabled.

We also need to add a dependency on HAS_IOMEM to make sure the
driver compiles correctly.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

drivers/mtd/nand/raw/Kconfig

@@ -460,7 +460,8 @@ config MTD_NAND_SH_FLCTL
 
 config MTD_NAND_DAVINCI
 	tristate "Support NAND on DaVinci/Keystone SoC"
-	depends on ARCH_DAVINCI || (ARCH_KEYSTONE && TI_AEMIF)
+	depends on ARCH_DAVINCI || (ARCH_KEYSTONE && TI_AEMIF) || COMPILE_TEST
+	depends on HAS_IOMEM
 	help
 	  Enable the driver for NAND flash chips on Texas Instruments
 	  DaVinci/Keystone processors.