drm/ast: removed optional dummy crtc mode_fixup function.

This patch set nukes all the dummy crtc mode_fixup implementations.
(made on top of Daniel topic/drm-misc branch)

Signed-off-by: Carlos Palminha <palminha@synopsys.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/0f8f948babd93fce8523253b0f525446e2f565db.1455630967.git.palminha@synopsys.com

drivers/gpu/drm/ast/ast_mode.c

@@ -497,13 +497,6 @@ static void ast_crtc_dpms(struct drm_crtc *crtc, int mode)
 	}
 }
 
-static bool ast_crtc_mode_fixup(struct drm_crtc *crtc,
-				const struct drm_display_mode *mode,
-				struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 /* ast is different - we will force move buffers out of VRAM */
 static int ast_crtc_do_set_base(struct drm_crtc *crtc,
 				struct drm_framebuffer *fb,
@@ -617,7 +610,6 @@ static void ast_crtc_commit(struct drm_crtc *crtc)
 
 static const struct drm_crtc_helper_funcs ast_crtc_helper_funcs = {
 	.dpms = ast_crtc_dpms,
-	.mode_fixup = ast_crtc_mode_fixup,
 	.mode_set = ast_crtc_mode_set,
 	.mode_set_base = ast_crtc_mode_set_base,
 	.disable = ast_crtc_disable,