regmap: irq: Add support for chips without separate IRQ status

regmap: irq: Add support for chips without separate IRQ status

Some GPIO chips allow to rise an IRQ on GPIO level changes but do not
provide an IRQ status for each separate line: only the current gpio
level can be retrieved.

Add support for these chips, emulating IRQ status by comparing GPIO
levels with the levels during the previous interrupt.

Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20250522-mdb-max7360-support-v9-5-74fc03517e41@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>