mfd: Add max7360 support

Add core driver to support MAX7360 i2c chip, multi function device
with keypad, GPIO, PWM, GPO and rotary encoder submodules.

Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
Co-developed-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250824-mdb-max7360-support-v14-2-435cfda2b1ea@bootlin.com


Signed-off-by: Lee Jones <lee@kernel.org>