iptables: add airoha patches to fix operation with modified structures

Econet makes arrays out of some single-element fields of iptables/ebtables structures. These arrays are processed like they are ranges of data. Thus the upstream iptables/ebtables break.

The use case in which ranges prove to be useful are rare, so typically it would be right to remove this change. However, we can't be sure that vendor blobs don't depend on these modified structures.

This patch implements an alternative solution: the modified structures are supported, however, the right-hand side of every range is filled with the left-hand side data. So, the changes to the user-visible interface are negligible.