V1: Add script to build UniversalPayload, which can be used after edksetup rebuild The final UPL.elf will be located at root folder of edk2 V2: Revise the ouput directory of generated files and coding style in the script Cc: Guo Dong <guo.dong@intel.com> Reviewed-by: Ray Ni <ray.ni@intel.com> Cc: Maurice Ma <maurice.ma@intel.com> Cc: Benjamin You <benjamin.you@intel.com> Cc: Zhiguang Liu <zhiguang.liu@intel.com> Cc: Bob Feng <bob.c.feng@intel.com> Signed-off-by: Dun Tan <dun.tan@intel.com>