V4L/DVB (10779): mxl5007t: remove analog tuning code

Analog doesn't work in this driver yet. This code just adds extra bloat,
so remove it for now.

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