feat(esp_libc): refactored POSIX timers get/set functions

- Added sys/timex.h and clock_adjtime API

components/esp_eth/include/esp_eth_clock.h

@@ -0,0 +1,81 @@
+/*
+ * SPDX-FileCopyrightText: 2024-2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include <sys/time.h>
+#include "esp_err.h"
+#include "esp_eth_driver.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef SOC_EMAC_IEEE1588V2_SUPPORTED
+
+/**
+ * @brief PTP clock identifier
+ *
+ */
+#define CLOCK_PTP_SYSTEM         ((clockid_t) 19)
+
+/**
+ * @brief Configuration of clock during initialization
+ *
+ */
+typedef struct {
+    clockid_t clock_id;
+} esp_eth_clock_cfg_t;
+
+/**
+ * @brief Set the target time for the PTP clock.
+ *
+ * @param clk_id Identifier of the clock to set the target time for
+ * @param tp Pointer to the target time
+ *
+ * @return
+ *     - 0: Success
+ *     - -1: Failure
+ */
+int esp_eth_clock_set_target_time(clockid_t clock_id, struct timespec *tp);
+
+/**
+ * @brief Register callback function invoked on Time Stamp target time exceeded interrupt
+ *
+ * @param clock_id Identifier of the clock
+ * @param ts_callback callback function to be registered
+ * @return
+ *     - 0: Success
+ *     - -1: Failure
+ */
+int esp_eth_clock_register_target_cb(clockid_t clock_id,
+                                     ts_target_exceed_cb_from_isr_t ts_callback);
+
+/**
+ * @brief Initialize the Ethernet PTP clock subsystem
+ *
+ * Enables PTP timestamping on the Ethernet MAC and registers the PTP clock
+ * with the POSIX time subsystem. After initialization, the clock is accessible
+ * via standard clock_gettime(CLOCK_PTP_SYSTEM, ...),
+ * clock_settime(CLOCK_PTP_SYSTEM, ...), and
+ * clock_adjtime(CLOCK_PTP_SYSTEM, ...) with ADJ_OFFSET / ADJ_FREQUENCY.
+ *
+ * @param eth_hndl Ethernet handle to initialize the clock for
+ * @param cfg Pointer to the configuration structure
+ *
+ * @return
+ *     - ESP_OK: Success
+ *     - ESP_FAIL: Failure
+ *     - ESP_ERR_INVALID_ARG: Invalid argument
+ *     - ESP_ERR_INVALID_STATE: Clock is already initialized
+ */
+esp_err_t esp_eth_clock_init(esp_eth_handle_t eth_hndl, const esp_eth_clock_cfg_t *cfg);
+
+#endif // SOC_EMAC_IEEE1588V2_SUPPORTED
+
+#ifdef __cplusplus
+}
+#endif