OvmfPkg/CpuHotplugSmm: add Qemu Cpu Status helper

OvmfPkg/CpuHotplugSmm: add Qemu Cpu Status helper

Add QemuCpuhpWriteCpuStatus() which will be used to update the QEMU
CPU status register. On error, it hangs in a similar fashion as
other helper functions.

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Aaron Young <aaron.young@oracle.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3132
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20210312062656.2477515-4-ankur.a.arora@oracle.com>