nouveau: ACPI support depends on X86 and X86_PLATFORM_DEVICES

If I build nouveau on ia64, Kconfig warns:

warning: (DRM_NOUVEAU) selects ACPI_WMI which has unmet direct dependencies (X86 && X86_PLATFORM_DEVICES && ACPI)
warning: (DRM_NOUVEAU) selects MXM_WMI which has unmet direct dependencies (X86 && X86_PLATFORM_DEVICES && ACPI_WMI)

Make all the ACPI support depend on X86 and select
X86_PLATFORM_DEVICES.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/Kconfig

@@ -11,8 +11,9 @@ config DRM_NOUVEAU
 	select FRAMEBUFFER_CONSOLE if !EXPERT
 	select FB_BACKLIGHT if DRM_NOUVEAU_BACKLIGHT
 	select ACPI_VIDEO if ACPI && X86 && BACKLIGHT_CLASS_DEVICE && VIDEO_OUTPUT_CONTROL && INPUT
-	select ACPI_WMI if ACPI
-	select MXM_WMI if ACPI
+	select X86_PLATFORM_DEVICES if ACPI && X86
+	select ACPI_WMI if ACPI && X86
+	select MXM_WMI if ACPI && X86
 	select POWER_SUPPLY
 	help
 	  Choose this option for open-source nVidia support.

drivers/gpu/drm/nouveau/Makefile

@@ -238,7 +238,9 @@ nouveau-y += nouveau_mem.o
 
 # other random bits
 nouveau-$(CONFIG_COMPAT) += nouveau_ioc32.o
+ifdef CONFIG_X86
 nouveau-$(CONFIG_ACPI) += nouveau_acpi.o
+endif
 nouveau-$(CONFIG_DRM_NOUVEAU_BACKLIGHT) += nouveau_backlight.o
 
 obj-$(CONFIG_DRM_NOUVEAU)+= nouveau.o

drivers/gpu/drm/nouveau/core/subdev/bios/base.c

@@ -172,7 +172,7 @@ nouveau_bios_shadow_prom(struct nouveau_bios *bios)
 	nv_wr32(bios, pcireg, access);
 }
 
-#if defined(CONFIG_ACPI)
+#if defined(CONFIG_ACPI) && defined(CONFIG_X86)
 int nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len);
 bool nouveau_acpi_rom_supported(struct pci_dev *pdev);
 #else

drivers/gpu/drm/nouveau/nouveau_acpi.h

@@ -3,7 +3,7 @@
 
 #define ROM_BIOS_PAGE 4096
 
-#if defined(CONFIG_ACPI)
+#if defined(CONFIG_ACPI) && defined(CONFIG_X86)
 bool nouveau_is_optimus(void);
 bool nouveau_is_v1_dsm(void);
 void nouveau_register_dsm_handler(void);