ipv4: raw: add drop reasons

[ Upstream commit 42186e6c ]

Use existing helpers and drop reason codes for RAW input path.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: e622502c ("ipmr: fix kernel panic when forwarding mcast packets")
Signed-off-by: Sasha Levin <sashal@kernel.org>