q35: Move options common to all classes to pc_q35_machine_options()

q35: Move options common to all classes to pc_q35_machine_options()

The existing default_machine_opts, default_display, no_floppy, and
no_tco settings will still apply to future machine classes. So it makes
sense to move them to pc_q35_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>