drm/amdgpu: don't skip attributes when powerplay is enabled

The function checks non-powerplay structures so regressed when
the pp_enabled check was removed.  This should ideally be
implemented similarly for powerplay.

Fixes: 6d07fe7b

 ("drm/amdgpu: delete pp_enable in adev")
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>