Add getters for `PortCfg` am: 28c5c1eb24

Original change: https://android-review.googlesource.com/c/trusty/lib/+/3504678

Change-Id: Icba0e266295d805fab3d3433268404c9e875ddd3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>