move functions in iceland_smc.c to iceland_smumgr.c
and make all functions in iceland_smumgr.c static.
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>