V4L/DVB (11796): xc5000: start using the newer "finerfreq" tuning command

Starting in firmware version 1.1.44, Xceive recommends using the FINERFREQ for
all normal tuning (the doc indicates reg 0x03 should only be used for fast
scanning for channel lock)

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>