net/mlx5: Use order-0 allocations for EQs

Currently we are allocating high-order page for EQs. In case of
fragmented system, VF hot remove/add in VMs for example, there isn't
enough contiguous memory for EQs allocation, which results in crashing
of the VM.
Therefore, use order-0 fragments for the EQ allocations instead.

Performance tests:
ConnectX-5 100Gbps, CPU: Intel(R) Xeon(R) CPU E5-2697 v3 @ 2.60GHz
Performance tests show no sensible degradation.

Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>