ARM: SMDK6410: Add initial support for WM1192-EV1 PMIC board

The Wolfson Microelectronics 1192-EV1 is a plug in module for the
SMDK6410 providing power using a WM8312 PMIC. This patch provides
initial hookup sufficient to initialise the board, though not all
features are fully described yet.

As part of this supplies for the system that are provided as a
single supply by one of the currently merged PMIC boards are
factored out so they can be reused between different regulators.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>