drm/cma: use correct fb width/height

What is passed to drm_fb_helper_fill_var() should be fb_width/fb_height,
rather than the surface size.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_fb_cma_helper.c

@@ -304,7 +304,7 @@ static int drm_fbdev_cma_create(struct drm_fb_helper *helper,
 	}
 
 	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->depth);
-	drm_fb_helper_fill_var(fbi, helper, fb->width, fb->height);
+	drm_fb_helper_fill_var(fbi, helper, sizes->fb_width, sizes->fb_height);
 
 	offset = fbi->var.xoffset * bytes_per_pixel;
 	offset += fbi->var.yoffset * fb->pitches[0];