Why do the pinout files not show a n leg of a differential pair for Arria V GZ devices?

Description

In Arria® V GZ device pinout files, not all pins belong to differential pairs. 

You may find there is only a DIFFIO_RX/TX_xyzp pin without a DIFFIO_RX/TX_xyzn pin.  Just treat these pins as single-ended I/O.