MIPS: SEAD3: Correct Ethernet node name

make dtbs_check:

    eth@1f010000: $nodename:0: 'eth@1f010000' does not match '^ethernet(@.*)?$'

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>