comm_components: eth_start initializes spi bus with SPI_DMA_CH_AUTO

Close https://github.com/espressif/esp-idf/issues/11083

examples/common_components/protocol_examples_common/eth_connect.c

@@ -122,7 +122,7 @@ static esp_netif_t *eth_start(void)
         .quadwp_io_num = -1,
         .quadhd_io_num = -1,
     };
-    ESP_ERROR_CHECK(spi_bus_initialize(CONFIG_EXAMPLE_ETH_SPI_HOST, &buscfg, 1));
+    ESP_ERROR_CHECK(spi_bus_initialize(CONFIG_EXAMPLE_ETH_SPI_HOST, &buscfg, SPI_DMA_CH_AUTO));
     spi_device_interface_config_t spi_devcfg = {
         .mode = 0,
         .clock_speed_hz = CONFIG_EXAMPLE_ETH_SPI_CLOCK_MHZ * 1000 * 1000,