LL: Disconnect on invalid MIC

[TorstenRobitzki]

LL/SEC/PER/BI-03-C and LL/SEC/PER/BI-04-C requires the IUT to disconnect the connection. It requires to not even acknowledge the received PDU.

The challenge here is, that in case, that the LL central resends a PDU, the MIC will also appear to be invalid, as the wrong counter is applied, when calculating the MIC. Solutions:

• Recalculate the MIC with the previous counter (counter will only be incremented for acknowledged PDUs)
• Keep the MIC (and maybe CRC) value of the last PDU for the connection.