net: ethernet: introduce IEEE802154 protocol
net: ethernet: introduce IEEE802154 protocol

This constant is required to prepare for introduction of AF_PACKET
support for IEEE 802.15.4 L2.

Signed-off-by: Florian Grandel <246eb2863b4e4387bb88d1fd54b2484fd4fc7b20@gmail.com>

zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr