mfd: adp5585: Add Analog Devices ADP5585 core support

mfd: adp5585: Add Analog Devices ADP5585 core support

The ADP5585 is a 10/11 input/output port expander with a built in keypad
matrix decoder, programmable logic, reset generator, and PWM generator.
This driver supports the chip by modelling it as an MFD device, with two
child devices for the GPIO and PWM functions.

The driver is derived from an initial implementation from NXP, available
in commit 8059835bee19 ("MLK-25917-1 mfd: adp5585: add ADI adp5585 core
support") in their BSP kernel tree. It has been extensively rewritten.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20240722121100.2855-3-laurent.pinchart@ideasonboard.com
Signed-off-by: Lee Jones <lee@kernel.org>