Remove the text stating that setting alarms is not yet supported, because it is, since PR #16180 Also document DS3231_PARAM_INT_PIN
tests/driver_ds3231 drivers/ds3231: add alarm support with IRQ drivers/ds3231: alarm support and documentation drivers/ds3231: alarm interrupt with mutex drivers/ds3231: alarm, _unlock function fixup! drivers/ds3231: add alarm support