Merge branch 'bugfix/eth_plus_wifi_doc' into 'master'

docs(esp_eth): added warning to not use ESP32 as ETH CLK source with WiFi

Closes DOC-8459

See merge request espressif/esp-idf!32736

docs/en/api-reference/network/esp_eth.rst

@@ -165,6 +165,9 @@ The Ethernet driver is composed of two parts: MAC and PHY.
 
             * Force the PHY device to reset status (as the case **a** in the picture). **This could fail for some PHY device** (i.e., it still outputs signals to GPIO0 even in reset state).
 
+        .. warning::
+            If you want the **Ethernet to work with Wi-Fi**, don’t select ESP32 as source of ``REF_CLK`` as it would result in ``REF_CLK`` instability. Either disable Wi-Fi or use a PHY or an external oscillator as the ``REF_CLK`` source.
+
     .. only:: not esp32
 
         .. note::