drm: Replace drm_format_plane_cpp() with fb->format->cpp[]

Replace drm_format_plane_cpp(fb->pixel_format) with just
fb->format->cpp[]. Avoids the expensive format info lookup.

@@
struct drm_framebuffer *a;
struct drm_framebuffer b;
expression E;
@@
(
- drm_format_plane_cpp(a->pixel_format, E)
+ a->format->cpp[E]
|
- drm_format_plane_cpp(b.pixel_format, E)
+ b.format->cpp[E]
)

@@
struct drm_plane_state *a;
struct drm_plane_state b;
expression E;
@@
(
- drm_format_plane_cpp(a->fb->pixel_format, E)
+ a->fb->format->cpp[E]
|
- drm_format_plane_cpp(b.fb->pixel_format, E)
+ b.fb->format->cpp[E]
)

@@
struct drm_framebuffer *a;
identifier T;
expression E;
@@
  T = a->pixel_format
<+...
- drm_format_plane_cpp(T, E)
+ a->format->cpp[E]
...+>

@@
struct drm_framebuffer b;
identifier T;
expression E;
@@
  T = b.pixel_format
<+...
- drm_format_plane_cpp(T, E)
+ b.format->cpp[E]
...+>

v2: Rerun spatch due to code changes

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1481751057-18123-1-git-send-email-ville.syrjala@linux.intel.com

drivers/gpu/drm/mediatek/mtk_drm_plane.c

@@ -135,7 +135,7 @@ static void mtk_plane_atomic_update(struct drm_plane *plane,
 	pitch = fb->pitches[0];
 	format = fb->pixel_format;
 
-	addr += (plane->state->src.x1 >> 16) * drm_format_plane_cpp(format, 0);
+	addr += (plane->state->src.x1 >> 16) * fb->format->cpp[0];
 	addr += (plane->state->src.y1 >> 16) * pitch;
 
 	state->pending.enable = true;