Revert "PM / Sleep: Unify diagnostic messages from device suspend/resume"

This reverts commit c89dd7871e29b60bf616ee36c228ab7e1fe14f1d.
Revert "PM / Docs: Recommend the use of [un]lock_system_sleep() over mutex_[un]lock(&pm_mutex)"

This reverts commit 3df27f537aa811e0fb167a789c26b025b3e666d0.
Revert "PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with [un]lock_system_sleep()"

This reverts commit 99273d27d6c5d37880fe05af44ff069bf12381ab.
Revert "PM / Sleep: Make [un]lock_system_sleep() generic"

This reverts commit ac8ea44a52182c1b4e03f411a469ff050a350808.
Revert "PM: Use the freezer_count() functions in [un]lock_system_sleep() APIs"

This reverts commit d467e4a9ae80be2523bbf5a98038513f28953ee2.