I found the pin multiplexing add-in for CCES ver 220.127.116.11 and added it to my project, which is just Automotive_Ethernet_AVB_Software-Rel2.4.0, Core0.
I was thinking that it would set up the GPIOs for me. It was a bit of work making sure that the add-in didn't change anything in the project. However, it is not clear how to use the add-in, since the GPIOs have no check-boxes. Please see the picture, NoChkBoxForGPIOsInThePinMuxAddIn.jpg, attached. I couldn't find any detailed help about this on the Analog.com website; the material I could find, such as EE372v01 - Getting Started with CCES.pdf, just says to use the add-in to select the peripheral signals that you want to enable. It also says that in the picture.
My confusion is that the GPIOs have no check-boxes to the left of them, giving no place to put a check to select them. Is there some correct understanding that I do not have, or is this an obvious problem? How does one select the GPIOs for output in pinmux using this tool?