Retain Switch status ESPHome after reboot and update / Ethernet setup

[S.Krans]

the switch yaml code you can add "restore_mode" for that.
fox example:
switch:
  - platform: gpio
    name: "Relay"
    pin: GPIO12  # your relay GPIO
    id: relay
    restore_mode: RESTORE_DEFAULT_ON  # or RESTORE_DEFAULT_OFF or ALWAYS_OFF/ALWAYS_ON

here is ESPHome about "restore_mode" setting details: https://esphome.io/components/switch/index.html

So like this 

Code:

  - platform: gpio
    name: "a128-light65"
    pin:
      pcf8574: pcf8574_hub_out_5
      number: 0
      mode: OUTPUT
      inverted: true
      restore_mode: RESTORE_DEFAULT_ON