drm_hwcomposer: Implement getDisplayPhysicalOrientation()

Implement ComposerClient::getDisplayPhysicalOrientation() by querying
the DRM display panel orientation property and translating the result to
the correct common::Transform enum value.

The result is used by SurfaceFlinger to correctly rotate the image
before displaying it to the user.

Signed-off-by: Tim Van Patten <timvp@google.com>
diff --git a/compositor/ColorInfo.h b/compositor/DisplayInfo.h
similarity index 81%
rename from compositor/ColorInfo.h
rename to compositor/DisplayInfo.h
index 1afda07..bbcbff8 100644
--- a/compositor/ColorInfo.h
+++ b/compositor/DisplayInfo.h
@@ -36,3 +36,13 @@
   kRgbWideFloat,
   kBt601Ycc,
 };
+
+/**
+ * Display panel orientation property values.
+ */
+enum PanelOrientation {
+  kModePanelOrientationNormal = 0,
+  kModePanelOrientationBottomUp,
+  kModePanelOrientationLeftUp,
+  kModePanelOrientationRightUp
+};