drm: arcpgu: arc_pgu_crtc_mode_valid() can be static

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170623095418.GA68865@lkp-sbx04
1 file changed