tests: boards: nrf: hwinfo: Add test for reset cause on nrf54*

Add test that checks reset cause reported by HWINFO.

Check that hwinfo_get_supported_reset_cause() returns
expected value.

Check that hwinfo_get_reset_cause() correctly detects:
- RESET_PIN,
- RESET_SOFTWARE,
- RESET_WATCHDOG.

Check that reset cause can be cleared
with hwinfo_clear_reset_cause().

Signed-off-by: Sebastian Głąb <sebastian.glab@nordicsemi.no>