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.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/clocking-wizard/Kconfig

@@ -5,6 +5,6 @@
 
 config COMMON_CLK_XLNX_CLKWZRD
 	tristate "Xilinx Clocking Wizard"
-	depends on COMMON_CLK && OF
+	depends on COMMON_CLK && OF && IOMEM
 	help
 	  Support for the Xilinx Clocking Wizard IP core clock generator.