libgralloc: Calculate aligned width & height using common header

For Venus, calculate aligned width & height using common header.

Change-Id: I622fee19693cfc550796d5949185c146c6a7f173
diff --git a/libgralloc/alloc_controller.cpp b/libgralloc/alloc_controller.cpp
index f0b2ca2..669ea08 100644
--- a/libgralloc/alloc_controller.cpp
+++ b/libgralloc/alloc_controller.cpp
@@ -236,6 +236,8 @@
             size = ALIGN(alignedw * alignedh * 2, 4096);
             break;
         case HAL_PIXEL_FORMAT_YCbCr_420_SP_VENUS:
+            alignedw = VENUS_Y_STRIDE(COLOR_FMT_NV12, width);
+            alignedh = VENUS_Y_SCANLINES(COLOR_FMT_NV12, height);
             size = VENUS_BUFFER_SIZE(COLOR_FMT_NV12, width, height);
             break;
         default: