net/mlx5e: Support MQPRIO channel mode

Add support for MQPRIO channel mode, in which a partition to TCs
is defined over the channels. We allow partitions with contiguous
queue indices, with no holes within. We do not allow modification
to the num of channels while this MQPRIO mode is active.

Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>