piix: Move pc-0.1[23] rombar compat props to PC_COMPAT_0_13

piix: Move pc-0.1[23] rombar compat props to PC_COMPAT_0_13

The VGA and vmware-svga rombar compat properties were added by commit
281a26b15b4adcecb8604216738975abd754bea8, but only to pc-0.13 and
pc-0.12. This breaks the PC_COMPAT_* nesting pattern we currently
follow.

The new variables will now be inherited by pc-0.11 and older, but
pc-0.11 and pc-0.10 already have PCI.rombar=0 on compat_props, so they
shouldn't be affected at all.

Cc: Stefan Weil <sw@weilnetz.de>
Cc: Gerd Hoffmann <kraxel@redhat.com>
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>