libhost1x/drm: support panel orientation property
libhost1x/drm: support panel orientation property

Now display will be auto-rotate in accordance to the panel's orientation
property of the connector. This is useful for devices like Nexus 7 that
have display panel mounted upside-down. It will work only using a very
recent kernel that supports the panel orientation.

grate-driver/grate,grate-driver/grate