Better support in RoboSwitch driver

Better support in RoboSwitch driver

I am terribly sorry, but because of a lack of testing equipment the
patch was submitted not properly tested.
Because the chipset documentation is not publicly available all
behaviour has to be found out by experimentation. The other day, I
made some incorrect assumptions based on my findings.

I do believe the attached patch does support the whole RoboSwitch line
(5325, 5350, 5352, 5365 and others). It is a drop-in substitution for
my previous submission.