x86/numachip: Add Numachip2 APIC support

Introduce support for Numachip2 remote interrupts via detecting the right
ACPI SRAT signature.

Access is performed via a fixed mapping in the x86 physical address space.

Signed-off-by: Daniel J Blueman <daniel@numascale.com>
Acked-by: Steffen Persvold <sp@numascale.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: http://lkml.kernel.org/r/1442768522-19217-2-git-send-email-daniel@numascale.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>