This reverts commit a4840d91.

Reverting due to power efficiency issues seen on Raven 1 and 2
when DPG mode is enabled.
Signed-off-by: Thong Thai <thong.thai@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>