mtd: rawnand: denali: Add the dependency on HAS_IOMEM

The helper function devm_platform_ioremap_resource_xxx()
needs HAS_IOMEM enabled, so add the dependency on HAS_IOMEM.

Fixes: 5f14a8ca ("mtd: rawnand: denali: Make use of the helper function devm_platform_ioremap_resource_byname()")

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20211109134758.417-1-caihuoqing@baidu.com