octeontx2-af: Limit KPU parsing for GTPU packets

With current KPU profile, while parsing GTPU packets, GTPU payload
is also being parsed and GTPU PDU payload is being treated as IPV4
data, which is not correct. In case of GTPU packets, parsing should
be stopped after identifying the GTPU. Adding changes to limit KPU
profile parsing for GTPU payload.

Signed-off-by: Kiran Kumar K <kirankumark@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>