soc: adi: max32: Use ceiling method to calculate exit latency ticks

The default 'near' mode results in zero exit latency ticks, which
prevents `sys_clock_set_timeout` from being called. This causes
the system to remain stuck in deep sleep modes. Use ceiling method
to obtain a nonzero exit latency tick count.

Signed-off-by: Tahsin Mutlugun <Tahsin.Mutlugun@analog.com>