arm64: dts: rockchip: describe mcu eeprom cells on rk3568-ts433

arm64: dts: rockchip: describe mcu eeprom cells on rk3568-ts433

The MCU's eeprom contains the unit's serial and a number of slots for
mac-addresses. As the MCU seems to be used in different devices, up to
8 mac addresses can live there and the unused slots are actually
initialized with empty mac-address strings like 00:00:00:00:05:09 .

Interestingly on the TS-433, the PCIe ethernet adapter brings its own
memory to hold its mac, and the gmac0 is supposed to get its mac from
the second mac-slot, while the first one stays empty.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20251112214206.423244-3-heiko@sntech.de