mtd: rawnand: sunxi: 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_SUNXI 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

@@ -516,7 +516,8 @@ config MTD_NAND_XWAY
 
 config MTD_NAND_SUNXI
 	tristate "Support for NAND on Allwinner SoCs"
-	depends on ARCH_SUNXI
+	depends on ARCH_SUNXI || COMPILE_TEST
+	depends on HAS_IOMEM
 	help
 	  Enables support for NAND Flash chips on Allwinner SoCs.