nfp: flower: reduce action list size by coalescing mangle actions

With the introduction of flow_action_for_each pedit actions are no
longer grouped together, instead pedit actions are broken out per
32 byte word. This results in an inefficient use of the action list
that is pushed to hardware where each 32 byte word becomes its own
action. Therefore we combine groups of 32 byte word before sending
the action list to hardware.
Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>