Patch adds generic size table that is similiar to rate table, with
difference that size table stores link layer packet size.

Based on patch by Patrick McHardy
 http://marc.info/?l=linux-netdev&m=115201979221729&w=2Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Stephen Hemminger <stephen.hemminger@vyatta.com>