Bluetooth: Use helper function to determine BR/EDR OOB data present

When replying to the IO capability request for Secure Simple Pairing and
Secure Connections, the OOB data present fields needs to set. Instead of
making the calculation inline, split this into a separate helper
function.

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