drm: qxl: Remove unused CRTC .dpms() helper operation

The CRTC .dpms() helper operation is called by the atomic helpers only
when no .prepare(), .atomic_disable() or .disable() operation is
provided. As the qxl driver provides a .disable() operation, the .dpms()
operation is unused and can be removed.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170627211621.27767-3-laurent.pinchart+renesas@ideasonboard.com

drivers/gpu/drm/qxl/qxl_display.c

@@ -378,10 +378,6 @@ qxl_framebuffer_init(struct drm_device *dev,
 	return 0;
 }
 
-static void qxl_crtc_dpms(struct drm_crtc *crtc, int mode)
-{
-}
-
 static bool qxl_crtc_mode_fixup(struct drm_crtc *crtc,
 				  const struct drm_display_mode *mode,
 				  struct drm_display_mode *adjusted_mode)
@@ -467,7 +463,6 @@ static void qxl_crtc_disable(struct drm_crtc *crtc)
 }
 
 static const struct drm_crtc_helper_funcs qxl_crtc_helper_funcs = {
-	.dpms = qxl_crtc_dpms,
 	.disable = qxl_crtc_disable,
 	.mode_fixup = qxl_crtc_mode_fixup,
 	.mode_set_nofb = qxl_mode_set_nofb,