drm/vmwgfx: Break out implicit fb code

Preparation for supporting explicit fbs for screen objects and screen
targets.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index 5cb1b16..b92521d 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -407,8 +407,9 @@
 	void *fb_info;
 	enum vmw_display_unit_type active_display_unit;
 	struct vmw_legacy_display *ldu_priv;
-	struct vmw_screen_object_display *sou_priv;
 	struct vmw_overlay *overlay_priv;
+	unsigned num_implicit;
+	struct vmw_framebuffer *implicit_fb;
 
 	/*
 	 * Context and surface management.