Add USAGE_OEM

Allow OEMs to pass data from other HW blocks via internal
extension.

Change-Id: I78c19f5eec462aff7d8a5408f2f16cfc9b78c036
diff --git a/rsDefines.h b/rsDefines.h
index 9287470..fdb0720 100644
--- a/rsDefines.h
+++ b/rsDefines.h
@@ -96,7 +96,8 @@
     RS_ALLOCATION_USAGE_IO_OUTPUT = 0x0040,
     RS_ALLOCATION_USAGE_SHARED = 0x0080,
 
-    RS_ALLOCATION_USAGE_ALL = 0x00FF
+    RS_ALLOCATION_USAGE_OEM = 0x8000,
+    RS_ALLOCATION_USAGE_ALL = 0x80FF
 };
 
 enum RsAllocationMipmapControl {