mfd: Add support for DA9061

mfd: Add support for DA9061

MFD support for DA9061 is provided as part of the DA9062 device driver.

The registers header file adds two new chip variant IDs defined in DA9061
and DA9062 hardware. The core header file adds new software enumerations
for listing the valid DA9061 IRQs and a da9062_compatible_types enumeration
for distinguishing between DA9061/62 devices in software.

The core source code adds a new .compatible of_device_id entry. This is
extended from DA9062 to support both "dlg,da9061" and "dlg,da9062". The
.data entry now holds a reference to the enumerated device type.

A new regmap_irq_chip model is added for DA9061 and this supports the new
list of regmap_irq entries. A new mfd_cell da9061_devs[] array lists the
new sub system components for DA9061. Support is added for a new DA9061
regmap_config which lists the correct readable, writable and volatile
ranges for this chip.

The probe function uses the device tree compatible string to switch on the
da9062_compatible_types and configure the correct mfd cells, irq chip and
regmap config.

Kconfig is updated to reflect support for DA9061 and DA9062 PMICs.

Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>