drm/amdgpu: add perfmon and fica atomics for df

adding perfmon and fica atomic operations to adhere to data fabrics finite
state machine requirements for indirect register access.

Signed-off-by: Jonathan Kim <Jonathan.Kim@amd.com>
Reviewed-by: Kent Russell <Kent.Russell@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>