net/mlx5e: Consider tunnel type for encap contexts

The driver allocates an encap context based on the tunnel properties,
and reuse that context for all flows using the same tunnel properties.
Commit df2ef3bf ("net/mlx5e: Add GRE protocol offloading")
introduced another tunnel protocol other than the single VXLAN
previously supported. A flow that uses a tunnel with the same tunnel
properties but with a different tunnel type (GRE vs VXLAN for example)
would mistakenly reuse the previous alocated context, causing the
traffic to be sent with the wrong encapsulation. Fix that by
considering the tunnel type for encap contexts.

Fixes: df2ef3bf ("net/mlx5e: Add GRE protocol offloading")
Signed-off-by: Eli Britstein <elibr@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>