net: dsa: bcm_sf2: Split rule handling from HW operation

In preparation for restoring CFP rules during system wide system
suspend/resume where the hardware loses its context, split the rule
validation from its actual insertion as well as the rule removal from
its actual hardware deletion operation.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>