esp_timer: remove legacy ESP32 FRC timer implementation.

components/newlib/platform_include/esp_newlib.h

@@ -1,16 +1,8 @@
-// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+/*
+ * SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
 
 #ifndef __ESP_NEWLIB_H__
 #define __ESP_NEWLIB_H__
@@ -53,9 +45,12 @@ void esp_setup_syscall_table(void) __attribute__((deprecated("Please call esp_ne
 void esp_set_time_from_rtc(void);
 
 /*
- * Sync counters RTC and FRC. Update boot_time.
+ * Sync timekeeping timers, RTC and high-resolution timer. Update boot_time.
  */
-void esp_sync_counters_rtc_and_frc(void);
+void esp_sync_timekeeping_timers(void);
+
+/* Kept for backward compatibility */
+#define esp_sync_counters_rtc_and_frc esp_sync_timekeeping_timers
 
 /**
  * Initialize newlib static locks