net/mlx5e: Fix inconsistent hairpin RQT sizes

The processing of traffic in hairpin queues occurs in HW/FW and does not
involve the cpus, hence the upper bound on max num channels does not
apply to them.  Using this bound for the hairpin RQT max_table_size is
wrong.  It could be too small, and cause the error below [1].  As the
RQT size provided on init does not get modified later, use the same
value for both actual and max table sizes.

[1]
mlx5_core 0000:08:00.1: mlx5_cmd_out_err:805:(pid 1200): CREATE_RQT(0x916) op_mod(0x0) failed, status bad parameter(0x3), syndrome (0x538faf), err(-22)

Fixes: 74a8dada ("net/mlx5e: Preparations for supporting larger number of channels")
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>