The response should not be EXOKAY unless an atomic access is requested
by the master using the LOCK signals.  This bridge does not even
support atomic accesses (it's an AXI4-Lite slave and does not have the
LOCK signals) so it's required to respond OKAY even if the master
does attempt an atomic access (this is how the master knows that the
slave does not support atomic accesses).  The AXI4-Lite specification
clearly states that the EXOKAY response is not supported in AXI4-Lite.