octeontx2-pf: Tc flower offload support for MPLS

This patch extends flower offload support for MPLS protocol.
Due to hardware limitation, currently driver supports lse
depth up to 4.

Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>