q35: Move options common to all classes to pc_i440fx_machine_options()

q35: Move options common to all classes to pc_i440fx_machine_options()

The existing default_machine_opts and default_display settings will
still apply to future machine classes. So it makes sense to move them to
pc_i440fx_machine_options() instead of keeping them in a
version-specific machine_options function.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>