What does the abbreviation IP in "System-on-Chip (SoC) infrastructure IP applications" stand for?
As already mentioned by Chetan, it stands for "Intellectual Property".

This Wikipedia article should make the context clearer:


  In electronic design a semiconductor intellectual property core, IP
  core, or IP block is a reusable unit of logic, cell, or chip layout
  design that is the intellectual property of one party. IP cores may be
  licensed to another party or can be owned and used by a single party
  alone.