Bluetooth: Mesh: Fix beacon_auth header net_id size
Bluetooth: Mesh: Fix beacon_auth header net_id size

The crypto.h declaration of the bt_mesh_beacon_auth function declares
the net_id parameter to be a 16 byte array, but the function definition
says 8 bytes. This breaks compilation in GCC 11, which feeds an 8 byte
array into this API, triggering a warning. Change the header declaration
to 8 bytes, which is the right size.

Signed-off-by: Trond Einar Snekvik <cbf21a7cf058d7ce8e74b0726695057d761f6ae9@nordicsemi.no>

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