This driver adds functionality to the tps65911 chip driver.

Two of the comparators are configurable by software and measures
VCCS voltage to detect high or low voltage scenarios.
Signed-off-by: NJorge Eduardo Candelaria <jedu@slimlogic.co.uk>
Acked-by: NSamuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>