refactor(usb/phy): Merge P4 and S2/S3 PHYs into one module

P4 had separate PHY implementation for initial bring-up,
now we can merge it with the original PHY driver.

components/usb/usb_host.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -469,7 +469,11 @@ esp_err_t usb_host_install(const usb_host_config_t *config)
         // Host Library defaults to internal PHY
         usb_phy_config_t phy_config = {
             .controller = USB_PHY_CTRL_OTG,
+#if CONFIG_IDF_TARGET_ESP32P4 // ESP32-P4 has 2 USB-DWC peripherals, each with its dedicated PHY. We support HS+UTMI only ATM.
+            .target = USB_PHY_TARGET_UTMI,
+#else
             .target = USB_PHY_TARGET_INT,
+#endif
             .otg_mode = USB_OTG_MODE_HOST,
             .otg_speed = USB_PHY_SPEED_UNDEFINED,   // In Host mode, the speed is determined by the connected device
             .ext_io_conf = NULL,