net/mlx5e: xsk: Use xsk_buff_alloc_batch on striding RQ
XSK provides a function to allocate frames in batches for more efficient
processing. This commit starts using this function on striding RQ and
creates an optimized flow for XSK. A side effect is an opportunity to
optimize the regular RX flow by dropping branching for XSK cases.
Performance improvement is up to 6.4% in the aligned mode and up to 7.5%
in the unaligned mode.