mtd: rawnand: brcmnand: 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 ARM, ARM64 or MIPS 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

@@ -354,7 +354,8 @@ config MTD_NAND_GPMI_NAND
 
 config MTD_NAND_BRCMNAND
 	tristate "Broadcom STB NAND controller"
-	depends on ARM || ARM64 || MIPS
+	depends on ARM || ARM64 || MIPS || COMPILE_TEST
+	depends on HAS_IOMEM
 	help
 	  Enables the Broadcom NAND controller driver. The controller was
 	  originally designed for Set-Top Box but is used on various BCM7xxx,