net/sched: move police action structures to header

Move tcf_police_params, tcf_police and tc_police_compat structures to a
header. Making them usable to other code for example drivers that would
offload police actions 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>