freertos: Remove legacy hooks

This commit refactors the legacy hooks as follows:

- Removed CONFIG_FREERTOS_LEGACY_HOOKS
- FreeRTOS hooks are now enabled via:
    - CONFIG_FREERTOS_USE_IDLE_HOOK
    - CONFIG_FREERTOS_USE_TICK_HOOK
- Update IDF hooks documentation

components/freertos/test/test_freertos_hooks.c

@@ -0,0 +1,86 @@
+/*
+ * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include <freertos/semphr.h>
+#include "unity.h"
+#include "test_utils.h"
+
+/*
+Test FreeRTOS idle hook. Only compiled in if FreeRTOS idle hooks are enabled.
+*/
+#if ( configUSE_IDLE_HOOK == 1 )
+
+static volatile unsigned idle_count;
+
+void vApplicationIdleHook(void)
+{
+    idle_count++;
+}
+
+TEST_CASE("FreeRTOS idle hook", "[freertos]")
+{
+    idle_count = 0;
+    vTaskDelay(10);
+    TEST_ASSERT_NOT_EQUAL(0, idle_count); // The legacy idle hook should be called at least once
+}
+
+#endif // configUSE_IDLE_HOOK
+
+/*
+Test the FreeRTOS tick hook. Only compiled in if FreeRTOS tick hooks are enabled.
+*/
+#if ( configUSE_TICK_HOOK == 1 )
+
+static volatile unsigned tick_count;
+
+void vApplicationTickHook(void)
+{
+    tick_count++;
+}
+
+TEST_CASE("FreeRTOS tick hook", "[freertos]")
+{
+    unsigned before = xTaskGetTickCount();
+    const unsigned SLEEP_FOR = 20;
+    tick_count = before;
+    vTaskDelay(SLEEP_FOR);
+    TEST_ASSERT_UINT32_WITHIN_MESSAGE(3 * portNUM_PROCESSORS, before + SLEEP_FOR * portNUM_PROCESSORS, tick_count,
+                                      "The FreeRTOS tick hook should have been called approx 1 time per tick per CPU");
+}
+
+#endif // configUSE_TICK_HOOK
+
+#if CONFIG_FREERTOS_ENABLE_STATIC_TASK_CLEAN_UP
+
+static volatile void *deleted_tcb;
+
+static void taskDeletesItself(void *ignored)
+{
+    vTaskDelete(NULL);
+}
+
+void vPortCleanUpTCB(void *pxTCB)
+{
+    deleted_tcb = pxTCB;
+}
+
+TEST_CASE("static task cleanup hook is called based on config", "[freertos]")
+{
+    for(int i = 0; i < portNUM_PROCESSORS; i++) {
+        printf("Creating task CPU %d\n", i);
+        TaskHandle_t new_task = NULL;
+        deleted_tcb = NULL;
+        xTaskCreatePinnedToCore(taskDeletesItself, "delete", 2048, NULL, UNITY_FREERTOS_PRIORITY, &new_task, i);
+        vTaskDelay(5);
+        TEST_ASSERT_EQUAL_PTR(deleted_tcb, new_task); // TCB & TaskHandle are the same in FreeRTOS
+    }
+}
+
+#endif // CONFIG_FREERTOS_ENABLE_STATIC_TASK_CLEAN_UP