gpio: Fix OF build problem on UM

The UserMode (UM) Linux build was failing in gpiolib-of as it requires
ioremap()/iounmap() to exist, which is absent from UM. The non-existence
of IO memory is negatively defined as CONFIG_NO_IOMEM which means we
need to depend on HAS_IOMEM.

Cc: [email protected]
Cc: Geert Uytterhoeven <[email protected]>
Reported-by: kbuild test robot <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>

Author: Linus Walleij

drivers/gpio/Kconfig

@@ -50,6 +50,7 @@ config GPIO_DEVRES
 config OF_GPIO
 	def_bool y
 	depends on OF
+	depends on HAS_IOMEM
 
 config GPIO_ACPI
 	def_bool y