axi_dmac: response_generator: Do not generate responses during ID sync

During an ID sync the request_id might increment, we should not generate a
response in this case. Since the ID sync only happens when the core is disabled
check that the core is enabled before generating a response.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

library/axi_dmac/response_generator.v

@@ -63,7 +63,7 @@ parameter C_ID_WIDTH = 3;
 assign resp_resp = RESP_OKAY;
 assign resp_eot = eot;
 
-assign resp_valid = request_id != response_id;
+assign resp_valid = request_id != response_id && enabled;
 
 // We have to wait for all responses before we can disable the response handler
 always @(posedge clk) begin