This s part of an import of the PVR-250 driver. Originally it was
calleed pvr250-setchannel, but it seems better to improve this program
to work for any tuner card, so I'm starting with a more generic name.
That shouldn't mislead anybody: currently the program only works with
the (yet to be committed) cxm driver.
Contributed by: John Wehle <john\@feith.com>