[ethernet] Add interface configuration variable for esp-idf (#10285)

Co-authored-by: J. Nick Koston <nick@home-assistant.io>
Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>
Co-authored-by: J. Nick Koston <nick@koston.org>

tests/components/ethernet/test-w5500.esp32-idf.yaml

@@ -1 +1,20 @@
-<<: !include common-w5500.yaml
+ethernet:
+  type: W5500
+  clk_pin: 19
+  mosi_pin: 21
+  miso_pin: 23
+  cs_pin: 18
+  interrupt_pin: 36
+  reset_pin: 22
+  clock_speed: 10Mhz
+  manual_ip:
+    static_ip: 192.168.178.56
+    gateway: 192.168.178.1
+    subnet: 255.255.255.0
+  domain: .local
+  mac_address: "02:AA:BB:CC:DD:01"
+  interface: spi2
+  on_connect:
+    - logger.log: "Ethernet connected!"
+  on_disconnect:
+    - logger.log: "Ethernet disconnected!"