SecurityPkg: TcgConfigDxe: Move TPM state string update to CallBack function

TPM state string update requires HiiHandle which may not be initialized when calling ExtractConfig.
Move this logic to CallBack function.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Chao Zhang <chao.b.zhang@intel.com>
Reviewed-by: Dandan Bi <dandan.bi@intel.com>