regulator (max5970): Fix IRQ handler

regulator (max5970): Fix IRQ handler

The max5970 datasheet gives the impression that IRQ status bits must
be cleared by writing a one to set bits, as those are marked with 'R/C',
however tests showed that a zero must be written.

Fixes an IRQ storm as the interrupt handler actually clears the IRQ
status bits.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
Link: https://msgid.link/r/20240130150257.3643657-1-naresh.solanki@9elements.com
Signed-off-by: Mark Brown <broonie@kernel.org>