drm/i810: add extern C guard for the UAPI header

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

include/uapi/drm/i810_drm.h

@@ -3,6 +3,10 @@
 
 #include "drm.h"
 
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
 /* WARNING: These defines must be the same as what the Xserver uses.
  * if you change them, you must change the defines in the Xserver.
  */
@@ -280,4 +284,8 @@ typedef struct _drm_i810_mc {
 	unsigned int last_render;	/* Last Render Request */
 } drm_i810_mc_t;
 
+#if defined(__cplusplus)
+}
+#endif
+
 #endif				/* _I810_DRM_H_ */