net: Introduce devicetree aware DEVICE define macros
net: Introduce devicetree aware DEVICE define macros

Provide versions of NET_DEVICE_INIT, NET_DEVICE_INIT_INSTANCE, and
NET_DEVICE_OFFLOAD_INIT that are both devicetree node and instance
aware.  We use the _DEFINE suffix for the DT versions to match the
naming convention in device.h

Signed-off-by: Kumar Gala <a5e5248af4cd4f0ed8c515f61d40a6e2db46a66e@linaro.org>

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