net/mlx5: enlarge maximal flow priority

net/mlx5: enlarge maximal flow priority

Currently, the maximal flow priority in non-root table to user
is 4, it's not enough for user to do some flow match by priority,
such as LPM, for one IPV4 address, we need 32 priorities for each
bit of 32 mask length.

PMD will manage 3 sub-priorities per user priority according to L2,
L3 and L4. The internal priority is 16 bits, user can use priorities
from 0 - 21843.

Those enlarged flow priorities are only used for ingress or egress
flow groups greater than 0 and for any transfer flow group.

Signed-off-by: Dong Zhou <dongzhou@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>