drm/amdgpu/powerplay: wire up BACO to powerplay API for smu7

Wire up the powerplay callbacks for for BACO for smu7 devices.

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