drm: Replace pitch with pitches[] in drm_framebuffer

Otherwise each driver would need to keep the information inside
their own framebuffer object structure. Also add offsets[]. BOs
on the other hand are driver specific, so those can be kept in
driver specific structures.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_legacy_crtc.c b/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
index 41a5d48..95b9360 100644
--- a/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
+++ b/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
@@ -437,7 +437,7 @@
 
 	crtc_offset_cntl = 0;
 
-	pitch_pixels = target_fb->pitch / (target_fb->bits_per_pixel / 8);
+	pitch_pixels = target_fb->pitches[0] / (target_fb->bits_per_pixel / 8);
 	crtc_pitch  = (((pitch_pixels * target_fb->bits_per_pixel) +
 			((target_fb->bits_per_pixel * 8) - 1)) /
 		       (target_fb->bits_per_pixel * 8));