Bluetooth: Remove OOB data if device was discovered in band

OOB authentication mechanism should be used only if pairing process
has been activated by previous OOB information exchange (Core Spec
4.0 , vol. 1, Part A, 5.1.4.3). Stored OOB data for specific device
should be removed if that device was discovered in band later on.

Signed-off-by: Szymon Janc <szymon.janc@tieto.com>
Acked-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>