gralloc: Fix UBWC related issues

1. Fix the missed ALIGN in getUBwcMetaBufferSize api.
2. Fix de-reference of data address pointer in getRgbDataAddress api.

Change-Id: I5dae2b6f449bb9a5b0dcc23110a2efce36060a42
diff --git a/libgralloc/mapper.cpp b/libgralloc/mapper.cpp
index 7d4e8ce..30f606e 100644
--- a/libgralloc/mapper.cpp
+++ b/libgralloc/mapper.cpp
@@ -445,7 +445,7 @@
         case GRALLOC_MODULE_PERFORM_GET_RGB_DATA_ADDRESS:
             {
                 private_handle_t* hnd = va_arg(args, private_handle_t*);
-                void* rgb_data = va_arg(args, void*);
+                void** rgb_data = va_arg(args, void**);
                 if (!private_handle_t::validate(hnd)) {
                     res = getRgbDataAddress(hnd, rgb_data);
                 }