net/mlx5: DR, Added support for REMOVE_HEADER packet reformat

ConnectX supports offloading of various encapsulations and decapsulations
(e.g. VXLAN), which are performed by 'Packet Reformat' action. Starting
with ConnectX-6 DX, a new reformat type is supported - REMOVE_HEADER, which
allows deleting an arbitrary size chunk at the selected position in the packet.

Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Reviewed-by: Alex Vesker <valex@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>