pinctrl: cix: Fix obscure dependency

When compile-testing for UM-Linux the build fails because
we don't have IOMEM.

Add an explicit dependency.

Fixes: 920500c ("pinctrl: cix: Add pin-controller support for sky1")
Reviewed-by: Peter Chen <peter.chen@cixtech.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Author: Linus Walleij

drivers/pinctrl/cix/Kconfig

@@ -9,6 +9,7 @@ config PINCTRL_SKY1_BASE
 config PINCTRL_SKY1
 	tristate "Cix Sky1 pinctrl driver"
 	depends on ARCH_CIX || COMPILE_TEST
+	depends on HAS_IOMEM
 	select PINCTRL_SKY1_BASE
 	help
 	  Say Y here to enable the sky1 pinctrl driver