net/mlx5e: Fix traffic being dropped on VF representor

Increase representor netdev RQ size to avoid dropped packets.
The current size (two) is just too small to keep up with
conventional slow path traffic patterns.
Also match the SQ size to the RQ size.

Fixes: cb67b832

 ("net/mlx5e: Introduce SRIOV VF representors")
Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>