gralloc: Enable framebuffer memory mapping.

Enable mapping from framebuffer if debug.gralloc.map_fb_memory
is set to 1. This is useful for bringup.

Change-Id: I3c860148729c5f5c98d84bf17e6633285b4b0af1
diff --git a/libgralloc/gpu.h b/libgralloc/gpu.h
index 6826ffe..8712c6c 100644
--- a/libgralloc/gpu.h
+++ b/libgralloc/gpu.h
@@ -51,6 +51,11 @@
                              int format, int usage,
                              buffer_handle_t* pHandle,
                              int* pStride);
+    int gralloc_alloc_framebuffer_locked(size_t size, int usage,
+                                         buffer_handle_t* pHandle);
+
+    int gralloc_alloc_framebuffer(size_t size, int usage,
+                                  buffer_handle_t* pHandle);
 
     static int gralloc_free(alloc_device_t* dev, buffer_handle_t handle);