DuetPkg: Remove DuetPkg

DuetPkg: Remove DuetPkg

DuetPkg depends on Legacy BIOS to provide a UEFI environment.
It was invented in the era when UEFI environment is hard to find.
Since now UEFI is very popular in PC area, we could stop the
official support of this package and remove it from the master.
https://bugzilla.tianocore.org/show_bug.cgi?id=1322

Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Hao Wu <hao.a.wu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
Reviewed-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>