gralloc: Modify check for uncompressed RGB buffers

The previous check for RGB formats skipped certain formats and hence
the alignment was incorrect.
Add a check for all non-compressed RGB formats before calling
getGpuAlignedWidthHeight

CRs-fixed: 888733

Change-Id: Icae4cfb92ceae5e593fd6c5658999fc90ef97ea1
diff --git a/libgralloc/gr.h b/libgralloc/gr.h
index 6d7f4a7..978d564 100644
--- a/libgralloc/gr.h
+++ b/libgralloc/gr.h
@@ -76,6 +76,9 @@
 // To query if UBWC is enabled, based on format and usage flags
 bool isUBwcEnabled(int format, int usage);
 
+// Function to check if the format is an uncompressed RGB format
+bool isUncompressedRgbFormat(int format);
+
 /*****************************************************************************/
 
 class Locker {