Bluetooth: Add HCI authentication capabilities macros

Add macros for the HCI capabilities as described in the Bluetooth Core
Specification v4.0, Volume 2, part E, section 7.1.29.

Signed-off-by: Mikel Astiz <mikel.astiz@bmw-carit.de>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>