display: Add Support for Rec.2020

- Add Rec2020 CSC in qdMetadata for limited/full range
- Expose CSC as #defines in gralloc private header to
  help GFX decouple from the display headers

Change-Id: I90ee2708275bf1a37ece0fce2f0867dfad64e39a
Crs-fixed: 1074164
diff --git a/libqdutils/qdMetaData.h b/libqdutils/qdMetaData.h
index 725e094..2b0b8c6 100644
--- a/libqdutils/qdMetaData.h
+++ b/libqdutils/qdMetaData.h
@@ -38,6 +38,8 @@
     ITU_R_601,
     ITU_R_601_FR,
     ITU_R_709,
+    ITU_R_2020,
+    ITU_R_2020_FR,
 };
 
 enum IGC_t {