regulator: core: Replace direct ops->disable usage

There are many places where ops->disable is called directly. Instead we
should use _regulator_do_disable() which also handles gpio regulators.

To be able to use the wrapper function from _regulator_force_disable(),
I moved the _notifier_call_chain() call from _regulator_do_disable() to
_regulator_disable(). This way, _regulator_force_disable() can use
different flags for _notifier_call_chain() without calling it twice.

Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>