pseries: DEFINE_SPAPR_MACHINE

pseries: DEFINE_SPAPR_MACHINE

At the moment all the class_init functions and TypeInfo structures for the
various versioned pseries machine types are open-coded.  As more versions
are created this is getting increasingly clumsy.

This patch borrows the approach used in PC, using a DEFINE_SPAPR_MACHINE()
macro to construct most of the boilerplate from simpler 'class_options' and
'instance_options' functions.

This patch makes a small semantic change - the versioned machine types are
now registered through machine_init() instead of type_init().  Since the
new way is how PC already did it, I'm assuming that's correct.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>