iio: adc: palmas: replace "wakeup" with "event"

iio: adc: palmas: replace "wakeup" with "event"

The palmas gpadc block has support for monitoring up to 2 ADC channels
and issue an interrupt if they reach past a set threshold. This is
currently used to wake up the system from sleep, but the functionality
is more generic than that. As such, change the naming of functions and
variables to refer to it as events instead, except during suspend and
resume where wakeup still make sense.

Signed-off-by: Patrik Dahlström <risca@dalakolonin.se>
Link: https://lore.kernel.org/r/20230408114825.824505-5-risca@dalakolonin.se
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>