You can't "configure" the port, but can use an ethernet jumper to connect E0 and PT on the back of the AP to achieve the same result.
The PT to E0/PT connection is a simple passive one; bridging PT to E0 on the back effectively moves E0 to the bottom E0/PT port.
You will need a low-profile, short and flexible ethernet jumper cable for that. We ship it with the AP-303H-MNTD desk mount and AP-303H-MNTW wall mount. We currentlly do not offer that as a separate orderable item. If you want to use the standard thin mount bracket that ships with the AP (to attach it to a wiring box) for direct wall mount, it will be a tight fit even with that cable. Which is why we offer the MNTW kit.
I may be able to get you a few to test it out. Please reach out by e-mail directly to onno@hpe.com if you're interested.