[media] dib0700: add initial code for PCTV 340e by Davide Ferri

This is initial code written by Davide Ferri for the PCTV 340e, including
a new xc4000 driver.  I am checking in all the code unmodified, and making
no assertions about its quality (other than confirming it compiles).

[mchehab@redhat.com: rebased on the top of the current tree]
Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Davide Ferri <davidef1986@gmail.com>
Cc: Patrick Boettcher <pboettcher@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>