Bluetooth: Add framework for Extended Controller Information

This command is used to retrieve the current state and basic
information of a controller. It is typically used right after
getting the response to the Read Controller Index List command
or an Index Added event (or its extended counterparts).

When any of the values in the EIR_Data field changes, the event
Extended Controller Information Changed will be used to inform
clients about the updated information.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Michał Narajowski <michal.narajowski@codecoup.pl>