disp: msm: sde: expose system cache support for writeback

Add a custom cache_enable property in writeback connector to allow
user-mode to control the cache setting on a frame basis. Configure
the hw and activate/deactivate the llcc based on the property. The
custom property is added based on the availability of the system
cache for writeback.

Change-Id: I812b31955eb36c75c33ac279b56502a13f7cdcbf
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>

msm/sde/sde_plane.h

@@ -356,7 +356,7 @@ bool sde_plane_is_cache_required(struct drm_plane *plane,
  * @state: state to set
  */
 void sde_plane_static_img_control(struct drm_plane *plane,
-		enum sde_crtc_cache_state state);
+		enum sde_sys_cache_state state);
 
 void sde_plane_add_data_to_minidump_va(struct drm_plane *plane);
 #endif /* _SDE_PLANE_H_ */