KVM: PPC: MPIC: Restrict to e500 platforms

The code as is doesn't compile on non-e500 platforms. Restrict it
there, so that people don't get into pitfalls of non-compiling code.

Signed-off-by: Alexander Graf <agraf@suse.de>
KVM: PPC: MPIC: Fix compiler warnings

I get the following compiler warnings:

  arch/powerpc/kvm/mpic.c: In function 'mpic_irq_raise':
  arch/powerpc/kvm/mpic.c:242:3: warning: format '%d' expects argument of type
        'int', but argument 4 has type 'long int' [-Wformat]
  arch/powerpc/kvm/mpic.c: In function 'mpic_irq_lower':
  arch/powerpc/kvm/mpic.c:260:3: warning: format '%d' expects argument of type
        'int', but argument 4 has type 'long int' [-Wformat]

This patches fixes these.

Signed-off-by: Alexander Graf <agraf@suse.de>