V4L/DVB: dvb: add support for kworld 340u and ub435-q to em28xx-dvb

This adds support for the KWorld PlusTV 340U and KWorld UB345-Q ATSC
sticks, which are really the same device. The sticks have an eMPIA
em2870 usb bridge chipset, an LG Electronics LGDT3304 ATSC/QAM
demodulator and an NXP TDA18271HD tuner -- early versions of the 340U
have a a TDA18271HD/C1, later models and the UB435-Q have a C2.

The stick has been tested succesfully with both VSB_8 and QAM_256 signals.
Its using lgdt3304 support added to the lgdt3305 driver by a prior patch,
rather than the current lgdt3304 driver, as its severely lacking in
functionality by comparison (see said patch for details).

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Michael Krufky <mkrufky@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>