speedtch: "extended reach"

The speedtouch modem setup code was reverse engineered many years
ago from a prehistoric windows driver. Less ancient windows drivers,
even those from a few years ago, perform extra initialization steps
which this patch adds to the linux driver.  David Woodhouse observed
that this initialization along with the firmware bin/sachu3/zzzlp2.eni
from the driver at
http://www.speedtouch.co.uk/downloads/330/301/UK3012%20Extended.zip


improves line sync speeds by about 20%.  He provided the original
patch, which I've modified to use symbolic names (BMaxDSL, ModemMode,
ModemOption) rather than magic numbers.  These names may not seem like
much of an improvement (after all, what is "ModemOption" exactly?),
but they do have one big advantage: they are the names used in the
windows registry.  I've made them available as module parameters.
Thanks are due to Aurelio Arroyo, who noticed the relationship
between these magic numbers and the entries in Phonebook.ini.

Signed-off-by: Duncan Sands <baldrick@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>