Bluetooth: Fix assuming EIR flags can result in SSP authentication

EIR flags should just hint if SSP may be supported but we shall verify
this with use of the actual features as the SSP bits may be disabled in
the lower layers which would result in legacy authentication to be
used.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>