V4L/DVB (4438): Fix dvb_pll_attach for nxt2004-based cards

The test in dvb-pll to see if a tuner's PLL responds when attaching fails
on NXT2004 based boards before the firmware is loaded.
This patch allows us to avoid this test by not passing an I2C bus handle to
the dvb_pll_attach routine, just as Chris Pascoe has done for MT352 and
ZL10353 based boards when used in cx88-dvb.

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>