net/mlx5e: Fix default amount of channels for VF representors

The default amount of channels a representor opens was erroneously
changed from one to the maximum amount of channels, restore to its
intended value.

Fixes: 779d986d ("net/mlx5e: Do not ignore netdevice TX/RX queues number")
Signed-off-by: Gavi Teitz <gavi@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>