Smartbond counter driver misses checking for unbalanced calls to policy state lock

[ioannis-karachalios]

Counter driver initialization fails when PM_DEVICE is declared (default state) because of unbalanced calls to pm_policy_state_lock_get and pm_policy_state_lock_put:

Issue can be reproduced by running the following test suite:

west build -b da1469x_dk_pro -p always tests/drivers/counter/counter_basic_api
west flash

#81200 is the PR that addresses the mentioned issue.