net/mlx5: fix RSS expansion with explicit next protocol

net/mlx5: fix RSS expansion with explicit next protocol

The PMD RSS expansion scheme by default compiles flow rules for all
flow item types that may branch out from a stub supplied
by application.
For example,
ETH can lead to VLAN, IPv4 or IPv6.
IPv4 can lead to UDP, TCP, IPv4 or IPv6.

If application explicitly specified next protocol type, expansion must
use that option only and not create flows with other protocol types.

The PMD ignored explicit next protocol values in GRE and VXLAN-GPE.

The patch updates RSS expansion for GRE and VXLAN-GPE with explicit
next protocol settings.

Fixes: c7870bfe09dc ("ethdev: move RSS expansion code to mlx5 driver")
Cc: stable@dpdk.org
Signed-off-by: Gregory Etelson <getelson@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>