net/mlx5e: Move Q counters allocation and drop RQ to init_rx

Not all profiles query the HW Q counters in update_stats() callback.
HW Q couners are limited per device and in case of representors all
their Q counters are allocated on the parent PF device.
Avoid reundant allocation of HW Q counters by moving the allocation
to init_rx profile callback.

Signed-off-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>