octeontx2-af: Allow mkex profile without DMAC and add L2M/L2B header extraction support

1. It is possible to have custom mkex profiles which do not extract
DMAC at all into the key. Hence allow mkex profiles which do not
have DMAC to be loaded into MCAM hardware. This patch also adds
debugging prints needed to identify profiles with wrong
configuration.

2. If a mkex profile set "l2l3mb" field for Rx interface,
then Rx multicast and broadcast entry should be configured.

Signed-off-by: Suman Ghosh <sumang@marvell.com>
Link: https://lore.kernel.org/r/20221031090856.1404303-1-sumang@marvell.com


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