Update nRF SDK submodule URL
url = https://github.com/contiki-ng/cc2640r2-sdk.git
[submodule "arch/cpu/nrf52840/lib/nrf52-sdk"]
path = arch/cpu/nrf52840/lib/nrf52-sdk
- url = https://github.com/alexstanoev/nrf-sdk-contiki-ng.git
+ url = https://github.com/contiki-ng/nrf-sdk-contiki-ng.git
