phy: uniphier-pcie: Depend on HAS_IOMEM

The driver uses devm_ioremap_resource() which is only available when
CONFIG_HAS_IOMEM is set, so the driver depends on this option.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>