net/sfc: allow PPPoE flow pattern items
net/sfc: allow PPPoE flow pattern items

These items allow the user to avoid having to set the EtherType field in an
ETH item to match PPPoE traffic. Using a PPPoED (PPPoE discovery) or PPPoES
(PPPoE session) item will lead to EtherType filter being set up with
a corresponding value. If an ETH item provides its own EtherType value,
it will be checked for correctness.

Matching on PPPoE fields is not supported.

Signed-off-by: Viacheslav Galaktionov <3b972c7ef5fe537152d23909a916cdcda27c5dc7@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <4155e7bf8e0185127625dac6d84336299844982f@oktetlabs.ru>
Reviewed-by: Andy Moreton <adbee5d9b6a6a553b71b14302d03837591e26c9d@xilinx.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk