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
diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
index 2e08f96..a606207 100644
--- a/drivers/gpu/drm/sun4i/sun4i_backend.c
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
@@ -218,7 +218,7 @@ int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend,
 	DRM_DEBUG_DRIVER("Using GEM @ %pad\n", &gem->paddr);
 
 	/* Compute the start of the displayed memory */
-	bpp = drm_format_plane_cpp(fb->pixel_format, 0);
+	bpp = fb->format->cpp[0];
 	paddr = gem->paddr + fb->offsets[0];
 	paddr += (state->src_x >> 16) * bpp;
 	paddr += (state->src_y >> 16) * fb->pitches[0];