Regulator updates in 3.5

There’s been a bit of an increase in the amount of core work in version 3.5, regmap has enabled a lot of code to be factored out of drivers and into the core so drivers only need to provide data. This makes things a lot simpler to implement and review, it’s hoped that it will also allow some framework enhancements for bulk operations in future.

• Helpers in the core for regulators using regmap, providing generic implementations of the enable and voltage selection operations which just need data to describe them in the drivers.
• Split out voltage mapping and voltage setting, allowing many more drivers to take advantage of the infrastructure for selectors.
• Support for Ricoh RC5T583, TI TPS62362, TI TPS62363, TI TPS65913, TI TWL6035, TI TWL6037