Bluetooth: Fix OOB data present for BR/EDR Secure Connections Only mode

When using Secure Connections Only mode, then only P-256 OOB data is
valid and should be provided. In case userspace provides P-192 and P-256
OOB data, then the P-192 values will be set to zero. However the present
value of the IO capability exchange still mentioned that both values
would be available. Fix this by telling the controller clearly that only
the P-256 OOB data is present.

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