mfd: Near complete mc13783 rewrite

This fixes several things while still providing the old API:

 - simplify and fix locking
 - better error handling
 - don't ack all irqs making it impossible to detect a reset of the
   rtc
 - use a timeout variant to wait for completion of ADC conversion
 - provide platform-data to regulator subdevice (This allows making
   struct mc13783 opaque for other drivers after the regulator driver is
   updated to use its platform_data.)
 - expose all interrupts
 - use threaded irq

After all users in mainline are converted to the new API, some things
(e.g. mc13783-private.h) can go away.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>