commit fbedf1c3 upstream.

Enable all three in the driver.  Early documentation
indicated the 3rd one was used for something else, but
that is not the case.

v2: handle disable as well
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[ kamal: backport to 3.13-stable: context ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>