Some PCI soundcards don't seem to use the generic gameport function with
interface 0x10 used here, but have either an own BAR dedicated to this
(i.e. Sonic Vibes or ESS Solo-1) or specify their own device (see
PCI_PRODUCT_CREATIVELABS_SBJOY in sys/dev/pci/pcidevs.h).
Probably these use a similar simple sheme and adding a frontend for them would
be trivial, but I don't own any of these cards, so I didn't.
