This new struct allows supporting unlimited number of ASPs per AS. It can also potentially be used in the future to: * Hold M3UA "ASP Identifier" per AS<->ASP association * Speed up iterating over AS served by a given ASP.
NOTE: Having >16 ASPs per AS may not be desirable, for instance under loadshare traffic mode ITU SLS is 4 bit, so despite having ext_sls extending the table to 128 entries based on OPC, it may not provide enough entropy to properly loadshare among all of them.