net/mlx5: fix build with dlopen linkage

net/mlx5: fix build with dlopen linkage

The header mlx5_glue.h includes rte_byteorder.h, which isn't
pulled by global_inc. This patch adds the missing include directory
and fixes the build error:

  In file included from drivers/net/mlx5/mlx5_glue.c:31:
  drivers/net/mlx5/mlx5_glue.h:12:10: fatal error:
  rte_byteorder.h: No such file or directory

The build failure can be triggered with:
  meson -Dibverbs_link=dlopen build && ninja -C build

Fixes: 400d985eb586 ("net/mlx5: add VLAN push/pop DR commands to glue")

Signed-off-by: Ali Alnubani <alialnu@mellanox.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>