This change decouples that upper activity-based logic from the lower random walk logic and allows use of other upper state detection logic (such as a custom, application-specific state machine).
1. open CONFIG_DEBUG_FEATURES CONFIG_SYSTEM_TIME64 CONFIG_CLOCK_MONOTONIC
==> INITIAL_SYSTEM_TIMER_TICKS very big data, not zero
2. close CONFIG_SCHED_TICKLESS
==> use g_system_timer as system clock
3. pm_domain_s.stime init to zero
4. clock_systimer() - pm_domain_s.stime get big data, error
libc/semaphore: Add nxsem_getvalue() which is identical to sem_getvalue() except that it never modifies the errno variable. Changed all references to sem_getvalue in the OS to nxsem_getvalue().
sched/semaphore: Rename all internal private functions from sem_xyz to nxsem_xyz. The sem_ prefix is (will be) reserved only for the application semaphore interfaces.
libc/semaphore: Add nxsem_init() which is identical to sem_init() except that it never modifies the errno variable. Changed all references to sem_init in the OS to nxsem_init().
sched/semaphore: Rename sem_tickwait() to nxsem_tickwait() so that it is clear this is an internal OS function.
sched/semaphoate: Rename sem_reset() to nxsem_reset() so that it is clear this is an internal OS function.
