Revert "UefiCpuPkg: Has APs in 64 bit long-mode before booting to OS."

Revert "UefiCpuPkg: Has APs in 64 bit long-mode before booting to OS."

This reverts commit 73ccde8f6d04a246377cabaed2875e69d4b6b719 since it
results in a hang of the IA32 processor and needs further clean-up.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4234
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Yuanhao Xie <yuanhao.xie@intel.com>