Bluetooth: Track local vs remote OOB data availability

There are several decisions in the SMP logic that depend not only on
whether we're doing SMP or not, but also whether local and/or remote OOB
data is present. This patch splits the existing SMP_FLAG_OOB into two
new flags to track local and remote OOB data respectively.

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