net/mlx5: DR, Fix SQ/RQ in doorbell bitmask

QP doorbell size is 16 bits.
Fixing sw steering's QP doorbel bitmask, which had 20 bits.
Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/steering/dr_send.c

@@ -213,7 +213,7 @@ static void dr_destroy_qp(struct mlx5_core_dev *mdev,
 static void dr_cmd_notify_hw(struct mlx5dr_qp *dr_qp, void *ctrl)
 {
 	dma_wmb();
-	*dr_qp->wq.sq.db = cpu_to_be32(dr_qp->sq.pc & 0xfffff);
+	*dr_qp->wq.sq.db = cpu_to_be32(dr_qp->sq.pc & 0xffff);
 
 	/* After wmb() the hw aware of new work */
 	wmb();