regulator: Pass regulator init data as explict argument when registering

Rather than having the regulator init data read from the platform_data
member of the struct device that is registered for the regulator make
the init data an explict argument passed in when registering. This
allows drivers to use the platform data for their own purposes if they
wish.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>