ARM: ux500: move ab8500_regulator_plat_data into driver

There is only one instance of ab8500_regulator_platform_data, and it's
safe to assume we won't ever merge another one, so it's rather pointless
to pass it through multiple levels of platform data pointers.

This moves the structure and everything referenced by it into the
driver that uses it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>