ntb_hw_switchtec: AND with the part_map for a valid tpart_vec

Some firmware versions return 1 in the target partition vector for
undefined partitions. AND with the part_map to give a valid tpart_vec.
Signed-off-by: Jeremy Pallotta <jmpallotta@gmail.com>
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

drivers/ntb/hw/mscc/ntb_hw_switchtec.c

@@ -858,6 +858,7 @@ static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)
 	tpart_vec |= ioread32(&sndev->mmio_ntb->ntp_info[self].target_part_low);
 
 	part_map = ioread64(&sndev->mmio_ntb->ep_map);
+	tpart_vec &= part_map;
 	part_map &= ~(1 << sndev->self_partition);
 
 	if (!tpart_vec) {