MdeModulePkg: Remove gZeroGuid definition in SetupBrowserDxe
    
    MdeModulePkg has defined gZeroGuid in 'Guid/ZeroGuid.h', therefore, the
    gZeroGuid defined in SetupBrowserDxe is redundant.
    
    Contributed-under: TianoCore Contribution Agreement 1.0
    Signed-off-by: Hao Wu <hao.a.wu@intel.com>
    Reviewed-by: Liming Gao <liming.gao@intel.com>
    Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>
    
    git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17839 6f19259b-4bc3-4df7-8a09-765794883524