OvmfPkg/AcpiPlatformDxe: Dynamically add Local APIC entries in MADT

OvmfPkg/AcpiPlatformDxe: Dynamically add Local APIC entries in MADT

Update MADT processing for QEMU to add additional Local APIC
entries to the MADT.

The MADT is still built with a single Local APIC entry.
If the AcpiPlatformDxe driver determines that more processors
are available, then additional Local APIC entries are added
to the MADT at runtime.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13387 6f19259b-4bc3-4df7-8a09-765794883524