Kernel: Move Scheduler current time method to the TimeManagement code

Author: https://github.com/supercomputer7
Commit: 7520acd4eb
Pull-request: https://github.com/SerenityOS/serenity/pull/15508
Reviewed-by: https://github.com/ADKaster
Reviewed-by: https://github.com/kleinesfilmroellchen ✅

Kernel/Time/TimeManagement.h

@@ -37,6 +37,8 @@ public:
     static bool is_initialized();
     static TimeManagement& the();
 
+    static u64 scheduler_current_time();
+
     static ErrorOr<void> validate_clock_id(clockid_t);
     Time current_time(clockid_t) const;
     Time monotonic_time(TimePrecision = TimePrecision::Coarse) const;