drm/amd/pm: use existing fini_smc_tables function for cyan skillfish

Remove redundant code and use general smu_v11_0_fini_smc_tables function.

Signed-off-by: Lang Yu <Lang.Yu@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>