[Why]
Need to get current DMUB time.

[How]
Add get_current_time interface to dmub_srv.

v2: drop whitespace changes (Alex)
Signed-off-by: NWyatt Wood <wyatt.wood@amd.com>
Reviewed-by: NAric Cyr <Aric.Cyr@amd.com>
Acked-by: NStylon Wang <stylon.wang@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>