regulator: max77686: Remove support for board files

regulator: max77686: Remove support for board files

The driver is used only on Exynos based boards with DTS support.
Simplify the driver and remove dead (unused) entries in platform_data
structure.

Convert the driver to DTS-only version. Parse all regulators at once,
not one-by-one. Remove dependency on data provided by max77686 MFD
driver. Use new DT style parsing method for regulators init data.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>