Bluetooth: refactor set_exp_feature with a feature table

This patch refactors the set_exp_feature with a feature table
consisting of UUIDs and the corresponding callback functions.
In this way, a new experimental feature setting function can be
simply added with its UUID and callback function.

Signed-off-by: Joseph Hwang <josephsih@chromium.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>