V4L/DVB (7718): pvrusb2-dvb: update Kbuild selections

These changes are required with the addition of digital television support
for the Hauppauge HVR1900 & HVR1950, the OnAir Creator and Sasem USB HDTV

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