drivers: ieee802154: nrf5: Support when LOG is off
drivers: ieee802154: nrf5: Support when LOG is off

ieee802154_nrf5 checks if IEEE802154_DRIVER_LOG_LEVEL is set to debug
before initializing the "nRF5 rx stack". This leads to an undefined
reference error in case of the LOG module being disabled.

Avoids this behavior by using the LOG_LEVEL macro and setting it as
LOG_LEVEL_NONE in case of IEEE802154_DRIVER_LOG_LEVEL not defined.

Signed-off-by: Joao Cordeiro <2e4d069a19cffb069f0f1fb8e5f8af1fab3d2d7a@cesar.org.br>

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