manifest: openthread upmerge to commit: 5cfbcfc
manifest: openthread upmerge to commit: 5cfbcfc

Regular OpenThread upmerge.

Signed-off-by: Lukasz Maciejonczyk <12a52743b42a5ad3dc4d3a6e4f8a76d0ad7c6806@nordicsemi.no>

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