EmulatorPkg: Change the cpu frequency to a non-zero value

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1686

The valuse of 1234 is a fake value for CPU frequency.

Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Andrew Fish <afish@apple.com>
Cc: Ray Ni <ray.ni@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>