drm: Nuke fb->depth

Replace uses of fb->depth with fb->format->depth. Less duplicate
information is a good thing.

@@
struct drm_framebuffer *fb;
expression E;
@@
 drm_helper_mode_fill_fb_struct(...) {
	...
-	fb->depth = E;
	...
 }

@@
struct nouveau_framebuffer *fb;
@@
- fb->base.depth
+ fb->base.format->depth

@@
struct drm_framebuffer fb;
@@
- fb.depth
+ fb.format->depth

@@
struct drm_framebuffer *fb;
@@
- fb->depth
+ fb->format->depth

@@
struct drm_framebuffer fb;
@@
- (fb.format->depth)
+ fb.format->depth

@@
struct drm_framebuffer *fb;
@@
- (fb->format->depth)
+ fb->format->depth

@@
@@
 struct drm_framebuffer {
	 ...
-	 unsigned int depth;
	 ...
 };

v2: Drop the vmw stuff (Daniel)
    Rerun spatch due to code changes

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1481751095-18249-1-git-send-email-ville.syrjala@linux.intel.com
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index e934b54..96c78b3 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1653,7 +1653,7 @@ void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helpe
 	info->var.height = -1;
 	info->var.width = -1;
 
-	switch (fb->depth) {
+	switch (fb->format->depth) {
 	case 8:
 		info->var.red.offset = 0;
 		info->var.green.offset = 0;