i2s: fixed i2s_ll compiling failure under C++ evironment

Closes: https://github.com/espressif/esp-idf/issues/11625

components/hal/include/hal/i2s_hal.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2020-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2020-2023 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -120,6 +120,15 @@ typedef struct {
  */
 void i2s_hal_init(i2s_hal_context_t *hal, int port_id);
 
+/**
+ * @brief Helper function for calculating the precise mclk division by sclk and mclk
+ *
+ * @param sclk      system clock
+ * @param mclk      module clock
+ * @param mclk_div  mclk division coefficients, including integer part and decimal part
+ */
+void i2s_hal_calc_mclk_precise_division(uint32_t sclk, uint32_t mclk, i2s_ll_mclk_div_t *mclk_div);
+
 /**
  * @brief Set tx channel clock
  *