[PATCH] hwmon: abituguru timeout fixes

This patch contains 2 sets of fixes for the abituguru:
 1) Much improved timeout handling, drasticly reducing the amount of
    timeout errors on some motherboards
 2) Fix the exit paths in the bank1 sensor type detect code to always
    restore the original settings even on an error. Without this our
    special test settings could remain seriously confusing the system
    BIOS's setup menu.

Both are very much related and are must haves, to avoid messing up the
uguru CMOS settings.

Detailed changes:
- Much improved timeout / wait for status handling. Many thanks to Sunil
  Kumar, for all his testing, ideas and patches! The code now first busy
  waits, polling the uguru for the expected status as this usually
  succeeds pretty quickly (within 90 reads). To avoid unnecessary CPU burn
  in timeout conditions, the amount of busy waiting has been halved from
  previous versions (120 tries instead of 250). This is not a problem,
  because this version goes to sleep afte...