Driver functionality

rio_setup_inb_dbell — bind inbound doorbell callback
rio_mport_get_feature — query for devices' extended features
RIO_LOP_READ — Generate rio_local_read_config_* functions
RIO_LOP_WRITE — Generate rio_local_write_config_* functions
RIO_OP_READ — Generate rio_mport_read_config_* functions
RIO_OP_WRITE — Generate rio_mport_write_config_* functions