[PATCH] fix nouveau build error on !CONFIG_MXM_WMI

[Fengguang Wu]

Fix build error on IA64:

ERROR: "mxm_wmi_supported" [drivers/gpu/drm/nouveau/nouveau.ko] undefined!

Signed-off-by: Fengguang Wu <fengguang.wu at intel.com>
---
 include/linux/mxm-wmi.h |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/linux/mxm-wmi.h b/include/linux/mxm-wmi.h
index 617a295..f6a6214 100644
--- a/include/linux/mxm-wmi.h
+++ b/include/linux/mxm-wmi.h
@@ -28,6 +28,14 @@
 #define MXM_MXDS_ADAPTER_IGD 0x10
 int mxm_wmi_call_mxds(int adapter);
 int mxm_wmi_call_mxmx(int adapter);
+
+#if IS_ENABLED(CONFIG_MXM_WMI)
 bool mxm_wmi_supported(void);
+#else
+static inline bool mxm_wmi_supported(void)
+{
+	return false;
+}
+#endif
 
 #endif
-- 
1.7.10