Unit node addresses should not have leading 0x:

  Warning (unit_address_format): /nemc@13410000/efuse@d0/eth-mac-addr@0x22: unit name should not have leading "0x"
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>