regmap: regmap-irq: silently ignore unsupported type settings

Do not return error if irq-type setting is requested for
controlloer which does not support this. This is how
regmap-irq has previously handled the undupported type
settings and existing drivers seem to be upset if failure
is now reported.

Fixes: 1c2928e3 ("regmap: regmap-irq/gpio-max77620: add level-irq support")
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>