drm/radeon: fix display handling in radeon_gpu_reset

If the display hw was reset or a hard reset was used,
we need to re-init some of the common display hardware as well.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

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