REGULATOR: TWL6025: add support to twl-regulator

Adding support for the twl6025. Major difference in the twl6025 is the
group functionality has been removed from the chip so this affects how
regulators are enabled and disabled.

The names of the regulators also changed.

The DCDCs of the 6025 are software controllable as well.

Since V1

Use the features variable passed via platform data instead of calling
global function.

Change the very switch like if statements to be a more readable
switch statement.

Since V2

twl6025 doesn't use remap so remove it from the macros.

Since V3

enable/disable functions for 4030/6030 were seperated upstream so rebase
on top of this. Change DCDC reference to SMPS as this is used in TRM.
Change list_voltage slightly to have less code.
Signed-off-by: Graeme Gregory <gg@slimlogic.co.uk>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>