PcdRealTimeClockUpdateTimeout is now defined in MdeModulePkg.dec. This is the only reason that causes PcAtChipsetPkg depends on MdeModulePkg. Move the PCD from MdeModulePkg.dec to PcAtChipsetPkg.dec removes such dependency. Signed-off-by: Ray Ni <ray.ni@intel.com> Reviewed-by: Hao A Wu <hao.a.wu@intel.com> Reviewed-by: Star Zeng <star.zeng@intel.com>