drm_hwcomposer: Set HDR metadata on the connector

Implement a function to set HDR metadata on the connector. Support HDR10
and HLG, which are common HDR types.

Change-Id: Id3dbe8eea2ee6b8ba700af23845a43e2070dd14e
Signed-off-by: Sasha McIntosh <sashamcintosh@google.com>
diff --git a/drm/DrmConnector.h b/drm/DrmConnector.h
index fc17206..c22d059 100644
--- a/drm/DrmConnector.h
+++ b/drm/DrmConnector.h
@@ -115,6 +115,10 @@
     return content_type_property_;
   }
 
+  auto &GetHdrOutputMetadataProperty() const {
+    return hdr_output_metadata_property_;
+  }
+
   auto &GetWritebackFbIdProperty() const {
     return writeback_fb_id_;
   }
@@ -169,6 +173,7 @@
   DrmProperty edid_property_;
   DrmProperty colorspace_property_;
   DrmProperty content_type_property_;
+  DrmProperty hdr_output_metadata_property_;
 
   DrmProperty link_status_property_;
   DrmProperty writeback_pixel_formats_;