gralloc: Add gralloc perform api to query RGB data address

A client can call GRALLOC_MODULE_PERFORM_GET_RGB_DATA_ADDRESS api
to get RGB data address for any linear or UBWC aligned RGB buffer.

Change-Id: I3a7d25f504b7ba1dec79cc872cafbb38ddbb6bd2
diff --git a/libgralloc/mapper.cpp b/libgralloc/mapper.cpp
index acac5b4..4a1b2cd 100644
--- a/libgralloc/mapper.cpp
+++ b/libgralloc/mapper.cpp
@@ -457,6 +457,15 @@
                 res = 0;
             } break;
 
+        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*);
+                if (!private_handle_t::validate(hnd)) {
+                    res = getRgbDataAddress(hnd, rgb_data);
+                }
+            } break;
+
         default:
             break;
     }