drm/radeon: fix resuming mode in pm runtime resume path

For runtime pm we'd never suspend with the modesetting hw turned on,
so don't try and resume the modesetting hw, as that path will take
locks that the interface that is causing us to wake up might also
take.

Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --cc drivers/gpu/drm/radeon/radeon_device.c
Simple merge