GenBiosId: Enable GenBiosId to set timestamp as zero

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2384



We need eliminate the effect of timestamp to verify
the reproducible build.

This patch is to add the support for GenBiosId to set
timestamp as zero.

Cc: Liming Gao <liming.gao@intel.com>
Cc: Steven Shi <steven.shi@intel.com>
Cc: Philippe Mathieu-Daude <philmd@redhat.com>
Signed-off-by: Bob Feng <bob.c.feng@intel.com>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>