drm: omapdrm: Don't flush CRTC when enabling or disabling it

The omap_crtc_flush() call in omap_crtc_enable() and omap_crtc_disable()
is a no-op, as the display manager is always disabled at this point. Just
remove the function call.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/omap_crtc.c

@@ -405,8 +405,6 @@ static void omap_crtc_enable(struct drm_crtc *crtc)
 			WARN_ON(omap_plane_setup(plane));
 	}
 
-	omap_crtc_flush(crtc);
-
 	drm_crtc_vblank_on(crtc);
 }
 
@@ -428,8 +426,6 @@ static void omap_crtc_disable(struct drm_crtc *crtc)
 		if (plane->crtc == crtc)
 			WARN_ON(omap_plane_setup(plane));
 	}
-
-	omap_crtc_flush(crtc);
 }
 
 static void omap_crtc_mode_set_nofb(struct drm_crtc *crtc)