Ethernet driver compile fix

[Jason2866]

Description:

fix compile when SPI Ethernet drivers are not enabled in IDF. Change logic to avoid EthType shift.

@s-hadinger please check. Thx.

Checklist:

• [x] The pull request is done against the latest development branch
• [x] Only relevant files were touched
• [x] Only one feature/fix was added per PR and the code change compiles without warnings
• [ ] The code change is tested and works with Tasmota core ESP8266 V.2.7.6
• [x] The code change is tested and works with Tasmota core ESP32 V.3.0.0
• [x] I accept the CLA.

NOTE: The code change must pass CI tests. Your PR cannot be merged unless tests pass

[s-hadinger]

Closing in favor of #21321