It makes more sense to pass an IPCState * to handlers of ICPStateClass
instead of a DeviceState *, if only to benefit from compile time type
checking. The same goes with ICSStateClass.

While here, we also change the declaration of ICPStateClass in xics.h
for consistency.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>