Add ready queue bitmap helper functions

When a task is enqueued into or dequeued from the ready queue, the
bitmap that indicates the ready queue state should be updated.

These two help functions can be used in relatives functions when
bitmap operations are required.

Author: vicLin8712

kernel/task.c

@@ -38,6 +38,18 @@ kcb_t *kcb = &kernel_state;
  */
 volatile bool scheduler_started = false;
 
+/* Bitmap functions */
+
+static inline void bitmap_set(uint8_t prio_level)
+{
+    kcb->ready_bitmap |= (1U << prio_level);
+}
+
+static inline void bitmap_clean(uint8_t prio_level)
+{
+    kcb->ready_bitmap &= ~(1U << prio_level);
+}
+
 /* timer work management for reduced latency */
 static volatile uint32_t timer_work_pending = 0;    /* timer work types */
 static volatile uint32_t timer_work_generation = 0; /* counter for coalescing */