AP_HAL_VRBRAIN: move delay callback handling to base HAL Scheduler class

libraries/AP_HAL_VRBRAIN/Scheduler.cpp

@@ -184,9 +184,7 @@ void VRBRAINScheduler::delay(uint16_t ms)
            !_vrbrain_thread_should_exit) {
         delay_microseconds_semaphore(1000);
         if (_min_delay_cb_ms <= ms) {
-            if (_delay_cb) {
-                _delay_cb();
-            }
+            call_delay_cb();
         }
     }
     perf_end(_perf_delay);
@@ -195,13 +193,6 @@ void VRBRAINScheduler::delay(uint16_t ms)
     }
 }
 
-void VRBRAINScheduler::register_delay_callback(AP_HAL::Proc proc,
-                                            uint16_t min_time_ms)
-{
-    _delay_cb = proc;
-    _min_delay_cb_ms = min_time_ms;
-}
-
 void VRBRAINScheduler::register_timer_process(AP_HAL::MemberProc proc)
 {
     for (uint8_t i = 0; i < _num_timer_procs; i++) {

libraries/AP_HAL_VRBRAIN/Scheduler.h

@@ -50,7 +50,6 @@ public:
     void     delay(uint16_t ms);
     void     delay_microseconds(uint16_t us);
     void     delay_microseconds_boost(uint16_t us);
-    void     register_delay_callback(AP_HAL::Proc, uint16_t min_time_ms);
     void     register_timer_process(AP_HAL::MemberProc);
     void     register_io_process(AP_HAL::MemberProc);
     void     register_timer_failsafe(AP_HAL::Proc, uint32_t period_us);
@@ -67,8 +66,6 @@ public:
 private:
     bool _initialized;
     volatile bool _hal_initialized;
-    AP_HAL::Proc _delay_cb;
-    uint16_t _min_delay_cb_ms;
     AP_HAL::Proc _failsafe;
 
     volatile bool _timer_suspended;