drm_hwcomposer: Add hotplug event handler

Add a hotplug event handler to handle hotplug events. Upon
hotplug, the handler is responsible for finding and setting
the preferred mode of the new display.

BUG=chrome-os-partner:41682
TEST=Tested on ryu with DP

Change-Id: Ide57382624c7839ed81a712bc29ea2e1cc19dcae
Signed-off-by: Sean Paul <seanpaul@chromium.org>
1 file changed