drm/amdgpu: don't enable baco on boco platforms in runpm

If the platform uses BOCO, don't use BACO in runtime suspend.
We could end up executing the BACO path if the platform supports
both.

Bug: drm/amd#1669


Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>