drm_hwcomposer: Add rotation support for hw planes

This patch adds support for transformed layers by using the
rotation property on drm planes.

Bug: chrome-os-partner:42093
Test: On smaug using
	adb shell content insert --uri content://settings/system --bind name:s:user_rotation --bind value:i:<R>

Change-Id: I86bb8ef2f77b5d046a5fddd57db4b87070b5801f
Signed-off-by: Sean Paul <seanpaul@chromium.org>
4 files changed