gpio: Fix OF build problem on UM

commit 2527ecc9 upstream.

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: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

arch/mips/kvm/kvm_mips.c

@@ -1211,7 +1211,7 @@ int __init kvm_mips_init(void)
 	 */
 	kvm_mips_gfn_to_pfn = gfn_to_pfn;
 	kvm_mips_release_pfn_clean = kvm_release_pfn_clean;
-	kvm_mips_is_error_pfn = is_error_pfn;
+	kvm_mips_is_error_pfn = is_error_noslot_pfn;
 
 	pr_info("KVM/MIPS Initialized\n");
 	return 0;

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