Bluetooth: Add basic documentation for address types
Bluetooth: Add basic documentation for address types

The Bluetooth address types were not documented, causing warnings from
Doxygen.

Fixes #3524

Signed-off-by: Johan Hedberg <628991c7b0a19c384f9b99c21ec330ce952bb838@intel.com>

ldts/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,ldts/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,ldts/zephyr,finikorg/zephyr,explora26/zephyr,explora26/zephyr,galak/zephyr,galak/zephyr,explora26/zephyr,punitvara/zephyr,punitvara/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,nashif/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,nashif/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,ldts/zephyr,finikorg/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,punitvara/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,galak/zephyr,punitvara/zephyr,punitvara/zephyr,nashif/zephyr,Vudentz/zephyr,nashif/zephyr,Vudentz/zephyr,nashif/zephyr,Vudentz/zephyr