WIP

WIP

* reduce u-boot-env parition to 128k
* add "para" partition which contains the label MAC address
  analog to TP-Link SG2452P v4 and few others
* add "empty" partition in between u-boot-env and para partitions
* use nvmem-layout for MAC address
* fix indentation in DTS
* replace edgecore,reboot with gpio-restart and use active-low
* remove adt7470@2f node, the adt7470 driver has no OF support
* remove chosen node, it is not needed
* remove ext-io@e4 node, we don't have a rtl8390-eio driver
* remove gpio-fan node, the fan is connected to and adt7470
* use EXTERNAL_PHY macro for phy 0-7
* add leds node with the gpio-leds driver
* enable uart1 for Nuvoton M0516 (PoE)
* fix PoE UCI defaults
* set phy-mode for PHY at address 48-51 to qsgmii
* add reset-gpios to mdio node
* add to DEVICE_PACKAGES:
  * kmod-eeprom-at24
  * kmod-hwmon-adt7470
  * kmod-hwmon-lm75
  * kmod-thermal
  * realtek-poe

Notes:

Did not manage to get a working link on the combo or SFP ports.
Tested mod-def0 and los GPIOs of all 4 SFP nodes, they are correct.
UTP port 9 and 10 work in U-Boot after running `rtk network on`.

Initramfs of this size boots fine when loading to address 0x8f000000
   Data Size:    8113317 Bytes = 7.7 MB

Having adt7470 and lm75 seems to cause random SFP unplug/plug events.
Unloading these modules stops that behaviour.