KVM: PPC: Book3S HV: Handle new LPCR bits on POWER8

POWER8 has a bit in the LPCR to enable or disable the PURR and SPURR
registers to count when in the guest.  Set this bit.

POWER8 has a field in the LPCR called AIL (Alternate Interrupt Location)
which is used to enable relocation-on interrupts.  Allow userspace to
set this field.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>