net: dsa: sja1105: Add P/Q/R/S support for dynamic L2 lookup operations

These are needed in order to implement the switchdev FDB callbacks.

Compared to the E/T generation, not only the ABI (bit offsets) is
different, but also the introduction of the HOSTCMD field which permits
O(1) TCAM search for an FDB entry.  Make use of the newly introduce
OP_SEARCH to permit that.  It will be used while adding and deleting an
FDB entry (to see whether it exists or not).

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>