gp4par: allow DACs to drive IOBs directly
gp4par: allow DACs to drive IOBs directly

rqou/openfpga,rqou/openfpga,azonenberg/openfpga,rqou/openfpga,azonenberg/openfpga,azonenberg/openfpga,azonenberg/openfpga,azonenberg/openfpga,rqou/openfpga,rqou/openfpga