[media] xc4000: setup dib7000p AGC config for PCTV 340e

Setup a proper AGC config for the 340e, based on the Windows USB trace

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>