gralloc: Add metadata type buffer_type

CRs-Fixed: 2730864
Change-Id: I8f96b5dc905f1b8cedc498d3853be27a8f92ae58
diff --git a/gralloc/QtiGralloc.h b/gralloc/QtiGralloc.h
index 4be74e2..9ab8732 100644
--- a/gralloc/QtiGralloc.h
+++ b/gralloc/QtiGralloc.h
@@ -109,6 +109,9 @@
 static const MetadataType MetadataType_VendorMetadataStatus = {VENDOR_QTI,
                                                                QTI_VENDOR_METADATA_STATUS};
 
+static const MetadataType MetadataType_BufferType = {VENDOR_QTI,
+                                                     QTI_BUFFER_TYPE};
+
 // 0 is also used as invalid value in standard metadata
 static const MetadataType MetadataType_Invalid = {VENDOR_QTI, 0};