clk: staging: Specify IOMEM dependency for Xilinx Clocking Wizard driver

clk: staging: Specify IOMEM dependency for Xilinx Clocking Wizard driver

The Xilinx Clocking Wizard driver uses the devm_ioremap_resource
function, but does not specify a dependency on IOMEM in Kconfig. This
causes a build failure on architectures without IOMEM, for example, UML
(notably with make allyesconfig).

Fix this by making CONFIG_COMMON_CLK_XLNX_CLKWZRD depend on CONFIG_IOMEM.

Signed-off-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/r/20200630044518.1084468-1-davidgow@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>