V4L/DVB (7354): tuner-simple: enable digital tuning support for Philips FCV1236D

Enable digital tuning support within tuner-simple. This will allow for a
single tuner module to manage the hardware, without having dvb-pll loaded.

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