include: Remove unused header
include: Remove unused header

This eth.h is not used anywhere and is a legacy header from first
network stack.

Signed-off-by: Tomasz Bursztyka <ba81a3a719836727e6857ae83462b9f52ec41006@linux.intel.com>

punitvara/zephyr,Vudentz/zephyr,kraj/zephyr,nashif/zephyr,galak/zephyr,nashif/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,punitvara/zephyr,ldts/zephyr,punitvara/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,Vudentz/zephyr,finikorg/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,kraj/zephyr,galak/zephyr,explora26/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,nashif/zephyr,punitvara/zephyr,explora26/zephyr,ldts/zephyr,explora26/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,kraj/zephyr,Vudentz/zephyr,finikorg/zephyr,galak/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,explora26/zephyr,ldts/zephyr,kraj/zephyr,GiulianoFranchetto/zephyr,punitvara/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,kraj/zephyr