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/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index beb0898..b726483 100644
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -261,7 +261,7 @@
 	/* This driver doesn't need a VT switch to restore the mode on resume */
 	info->skip_vt_switch = true;
 
-	drm_fb_helper_fill_fix(info, fb->pitches[0], fb->depth);
+	drm_fb_helper_fill_fix(info, fb->pitches[0], fb->format->depth);
 	drm_fb_helper_fill_var(info, &ifbdev->helper, sizes->fb_width, sizes->fb_height);
 
 	/* If the object is shmemfs backed, it will have given us zeroed pages.