regulators: Updated ab8500 variable names, macro names and comments

The regulator enumeration is used for putting the regulator data
in correct place in the info array. This should be matched in the
board configuration.

Variable names are updated to be more consistent, comments are
corrected and macros have been edited to be consistent.

Signed-off-by: Bengt Jonsson <bengt.g.jonsson@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>