common/mlx5: fix umem buffer alignment

common/mlx5: fix umem buffer alignment

The value MLX5_WQE_BUF_ALIGNMENT is defined as 512.
In some cases this alignment size is not adequate, which results in
memory registration that is not accepted by FW.
The result error can be "page_offset is not aligned to page_size/64,
bad umem_offset" (syndrome 0x357275).

This patch updates the definition to match the running system.

Fixes: 18a68e046b51 ("net/mlx5: fix DevX Rx queue memory alignment")
Cc: stable@dpdk.org
Signed-off-by: Dekel Peled <dekelp@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>