V4L/DVB (6962): tda18271: allow device-specific configuration of IF frequency and std bits

Allow drivers to pass device-specific configuration parameters during attach.

If these parameters are omitted, default values will be used.

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