feat(eth): Add support for generic IEEE 802.3 driver

Author: me-no-dev

Diff for: libraries/Ethernet/src/ETH.cpp

@@ -283,6 +283,7 @@ bool ETHClass::begin(eth_phy_type_t type, int32_t phy_addr, int mdc, int mdio, i
 
   esp_eth_phy_t *phy = NULL;
   switch (type) {
+    case ETH_PHY_GENERIC: phy = esp_eth_phy_new_generic(&phy_config); break;
     case ETH_PHY_LAN8720: phy = esp_eth_phy_new_lan87xx(&phy_config); break;
     case ETH_PHY_TLK110:  phy = esp_eth_phy_new_ip101(&phy_config); break;
     case ETH_PHY_RTL8201: phy = esp_eth_phy_new_rtl8201(&phy_config); break;

Diff for: libraries/Ethernet/src/ETH.h

@@ -78,6 +78,7 @@
 
 #if CONFIG_ETH_USE_ESP32_EMAC
 #define ETH_PHY_IP101 ETH_PHY_TLK110
+#define ETH_PHY_JL1101 ETH_PHY_GENERIC
 #if CONFIG_IDF_TARGET_ESP32
 typedef enum {
   ETH_CLOCK_GPIO0_IN,
@@ -127,6 +128,7 @@ typedef emac_rmii_clock_mode_t eth_clock_mode_t;
 
 typedef enum {
 #if CONFIG_ETH_USE_ESP32_EMAC
+  ETH_PHY_GENERIC,
   ETH_PHY_LAN8720,
   ETH_PHY_TLK110,
   ETH_PHY_RTL8201,