regmap-irq: Remove an unnecessary restriction on type_in_mask

Check types_supported instead of checking type_rising/falling_val
when using type_in_mask interrupts. This makes the intent clearer
and allows a type_in_mask irq to support level or edge triggers,
rather than only edge triggers.

Update the documentation and comments to reflect the new behavior.

This shouldn't affect existing drivers, because if they didn't
set types_supported properly the type buffer wouldn't be updated.

Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
Link: https://lore.kernel.org/r/20220623211420.918875-5-aidanmacdonald.0x0@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>