regmap: irq: Use one way of setting all bits in the register

Currently there are two ways of how we represent all bits set, i.e.
UINT_MAX and GENMASK(31, 0). Use the former as the single way of
doing that, which is crystal clear on how we fill the unsigned int
value.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20250206191644.1132869-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>