ARM: dts: sun8i: Add ethernet1 alias to Orange Pi 2 dts

This will allow u-boot to fill in a mac-address for Orange Pi 2
variants which use an sdio wifi without an eeprom for the mac.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>