net: mscc: ocelot: unexpose ocelot_vcap_policer_{add,del}

Remove the function prototypes from ocelot_police.h and make these
functions static. We need to move them above their callers. Note that
moving the implementations to ocelot_police.c is not trivially possible
due to dependency on is2_entry_set() which is static to ocelot_vcap.c.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>