V4L/DVB (12902): Documentation: synchronize documentation for Technisat cards

The patch does the following:

a. it synchronizes /Documentation/dvb/technisat.txt to the current kernel
design
b. it syncs Trent Piepho' s latest changes to the flexcop driver concept:
implementation of the dvb pll library for some cards that need it

Signed-off-by: Uwe Bugla <uwe.bugla@gmx.de>
Signed-off-by: Patrick Boettcher <pboettcher@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>