drm/radeon: dpm fixes for asrock systems

- bapm seems to cause CPU stuck messages so disable it.
- nb dpm seems to prevent GPU dpm from getting enabled, so
disable it.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=85107



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