UefiCpuPkg/UefiCpuPkg.uni: Add the prompt and help information

UefiCpuPkg/UefiCpuPkg.uni: Add the prompt and help information

The prompt and help information are missing in UefiPkg.uni.
https://bugzilla.tianocore.org/show_bug.cgi?id=1600

v3:The changes in v1 are duplicated. So update the info.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>