bluetooth: smp: CTKD issue when cross br and ble connections and security

The peer uses the RPA address.
A BR connection is created firstly, a subsequent BLE connection is
created secondly, the BR SMP CTKD occur thirdly (The BLE LTK is
derived from BR and the BR SMP distribute peer's IRK and identity address
here), but the BLE LTK is saved to key pool that is not
matched with the previous BLE connection because the derived LTK is saved
with identity address and BLE connection uses RPA. Fix it by: Resolve the
BLE connections' RPA with the derived IRK to find the previous BLE
connections and match the connections with derived LTK key.

Signed-off-by: Mark Wang <yichang.wang@nxp.com>