Bluetooth: Add definitions for advertisement monitor features

This adds support for Advertisement Monitor API. Here are the commands
and events added.
- Read Advertisement Monitor Feature command
- Add Advertisement Pattern Monitor command
- Remove Advertisement Monitor command
- Advertisement Monitor Added event
- Advertisement Monitor Removed event

Signed-off-by: Miao-chen Chou <mcchou@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>