This reverts commit 51bfac71.

This causes stability issues on some raven boards.  Revert
for now until a proper fix is completed.

Bug: https://gitlab.freedesktop.org/drm/amd/issues/934
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=206017Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>