mfd: Remove obsolete mc13783 private data

The regulator driver was converted to get the needed data directly from
platform_data by

	a10099bc (regulator/mc13783: various cleanups)

so regulators and num_regulators can go away.  Then apart from the flag
indicating that the adc does a conversion, flags is only a copy of the
flags member of platform_data.  This flag isn't needed to be returned by
mc13783_get_flags, so mc13783_get_flags now gets the flags from
platform_data, too and the driver private member is renamed for clearity.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>