Implement suspending all gangs.
Signed-off-by: NJack Xiao <Jack.Xiao@amd.com>
Acked-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NHawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>