octeontx2-af: Set proper errorcode for IPv4 checksum errors

With current config, for packets with IPv4 checksum errors,
errorcode is being set to UNKNOWN. Hence added a separate
errorcodes for outer and inner IPv4 checksum and changed
NPC configuration accordingly.

Also turn on L2 multicast address check in NPC protocol check block.

Fixes: 6b3321ba ("octeontx2-af: Enable packet length and csum validation")
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>