net: mvpp2: prs: improve ipv4 parse flow

Patch didn't fix any issue, just improve parse flow
and align ipv4 parse flow with ipv6 parse flow.

Currently ipv4 kenguru parser first check IP protocol(TCP/UDP)
and then destination IP address.
Patch introduce reverse ipv4 parse, first destination IP address parsed
and only then IP protocol.
This would allow extend capability for packet L4 parsing and align ipv4
parsing flow with ipv6.

Suggested-by: Liron Himi <liron@marvell.com>
Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Link: https://lore.kernel.org/r/1610289059-14962-1-git-send-email-stefanc@marvell.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>