Move the ifaceMacvtapLinkDump and ifaceGetNthParent functions
into virnetdevvportprofile.c since they are specific to that
code. This avoids polluting the headers with the Linux specific
netlink data types

* src/util/interface.c, src/util/interface.h: Move
  ifaceMacvtapLinkDump and ifaceGetNthParent functions and delete
  remaining file
* src/util/virnetdevvportprofile.c: Add ifaceMacvtapLinkDump
  and ifaceGetNthParent functions
* src/network/bridge_driver.c, src/nwfilter/nwfilter_gentech_driver.c,
  src/nwfilter/nwfilter_learnipaddr.c, src/util/virnetdevmacvlan.c:
  Remove include of interface.h