feat(i2c_master): Add an api for retrieveing handle via port,

Closes https://github.com/espressif/esp-idf/issues/13968

components/esp_driver_i2c/include/esp_private/i2c_platform.h

@@ -0,0 +1,36 @@
+/*
+ * SPDX-FileCopyrightText: 2023-2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include "esp_err.h"
+#include "driver/i2c_types.h"
+#include "hal/gpio_types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Retrieves the I2C master bus handle for a specified I2C port number.
+ *
+ * This function retrieves the I2C master bus handle for the
+ * given I2C port number. Please make sure the handle has already been initialized, and this
+ * function would simply returns the existing handle. Note that the returned handle still can't be used concurrently
+ *
+ * @param port_num I2C port number for which the handle is to be retrieved.
+ * @param ret_handle Pointer to a variable where the retrieved handle will be stored.
+ * @return
+ *     - ESP_OK: Success. The handle is retrieved successfully.
+ *     - ESP_ERR_INVALID_ARG: Invalid argument, such as invalid port number
+ *     - ESP_ERR_INVALID_STATE: Invalid state, such as the I2C port is not initialized.
+ */
+esp_err_t i2c_master_get_bus_handle(i2c_port_num_t port_num, i2c_master_bus_handle_t *ret_handle);
+
+#ifdef __cplusplus
+}
+#endif