Frequency units in V4L2 are apparently different when in radio mode
compared to tv mode.  Why?  Who knows.  This change adapts the driver
appropriately - so that internally we always only deal in Hz and don't
have to muck with craziness like this.
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>