platsupport: Exynos PMIC/PMIC-RTC: Update drivers with improved I2C API

* KVslave library initialization is a separate step from slave init.
* We now require a separate handle for the KVslave library which operates
as a layer on top of an I2C slave.

pragma once and for all

Fix whitespace

- remove trailing whitespace
- remove duplicate blank lines
- remove blank lines at end of file

fix licenses