arch: update port terminology

arch: update port terminology

Change-Id: Ifcf90534d8e5ff5fc68538ec87dc541517ea404d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/32311
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>