Add PMU IRQ to Apic table

Signed-off-by: Mark Salter <msalter@redhat.com>
Fix Mcfg bus range

The Mustang PCIe bridge only decodes bus 0 (which only contains
bridge itself) with mmconfig. Reflect that in the MCFG table.

Signed-off-by: Mark Salter <msalter@redhat.com>