esp_hw_support: Move rtc.h header from target components

components/esp_hw_support/include/soc/esp32s3/rtc.h

@@ -0,0 +1,39 @@
+// Copyright 2015-2017 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.
+
+#pragma once
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @file esp32s2/rtc.h
+ *
+ * This file contains declarations of rtc related functions.
+ */
+
+/**
+ * @brief Get current value of RTC counter in microseconds
+ *
+ * Note: this function may take up to 1 RTC_SLOW_CLK cycle to execute
+ *
+ * @return current value of RTC counter in microseconds
+ */
+uint64_t esp_rtc_get_time_us(void);
+
+#ifdef __cplusplus
+}
+#endif