Bluetooth: controller: Add macro with minimum allowed adv. PDU size
Bluetooth: controller: Add macro with minimum allowed adv. PDU size

To check if advertising PDU is empty we can compare its length to 1.
To avoid use of magic number, the commit provides a macro for that
purpose.

Signed-off-by: Piotr Pryga <4cae3388a6c6e480df2109bb21aa832bf2c59595@nordicsemi.no>

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