disp: msm: snapshot change for mdp driver to support multiple SIs

This change adds support in mdp and dsi driver to support
multiple SIS.

Change-Id: I432068cea17e1784d7570a472fbadaa86695df07
Signed-off-by: Narendra Muppalla <NarendraM@codeaurora.org>
Signed-off-by: Amine Najahi <anajahi@codeaurora.org>

msm/msm_drv.h

@@ -1150,6 +1150,8 @@ int msm_gem_get_iova(struct drm_gem_object *obj,
 		struct msm_gem_address_space *aspace, uint64_t *iova);
 uint64_t msm_gem_iova(struct drm_gem_object *obj,
 		struct msm_gem_address_space *aspace);
+void msm_gem_unpin_iova(struct drm_gem_object *obj,
+		struct msm_gem_address_space *aspace);
 struct page **msm_gem_get_pages(struct drm_gem_object *obj);
 void msm_gem_put_pages(struct drm_gem_object *obj);
 void msm_gem_put_iova(struct drm_gem_object *obj,