Stutter mode is a power saving feature on GPUs, however at
least one early raven system exhibits stability issues with
it.  Add a quirk to disable it for that system.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=214417


Fixes: 00544006 ("drm/amdgpu: enable gfxoff again on raven series (v2)")
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>