x86: Turn the local APIC into a PioDevice instead of a BasicPioDevice.

x86: Turn the local APIC into a PioDevice instead of a BasicPioDevice.

This will let us accept several address ranges through our pio port
instead of just one, and that will in turn let us accept interrupt
requests and pio requests through the same port.

Change-Id: I70b78c8cd0edca7fe58b3d4cd241e41d9e0f2c20
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20819
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>