gralloc: Use adreno_utils api for NV21 and NV12 alignment

Use adreno_utils api to get stride alignment requirement by GPU for
NV21 & NV12 formats. It is required to keep Camera & Gralloc in sync.

CRs-Fixed: 880927
Change-Id: Ie71f864c975e38fe4aa58735cc8ffe9dd0734f4f
diff --git a/libgralloc/gr.h b/libgralloc/gr.h
index 6d7f4a7..f8b1577 100644
--- a/libgralloc/gr.h
+++ b/libgralloc/gr.h
@@ -191,5 +191,7 @@
                                                 int *bpp);
 
         int (*LINK_adreno_isUBWCSupportedByGpu) (ADRENOPIXELFORMAT format);
+
+        unsigned int (*LINK_adreno_get_gpu_pixel_alignment) ();
 };
 #endif /* GR_H_ */