lib: smc: Add smc18/hvc18 am: d3165253dc

Original change: https://android-review.googlesource.com/c/trusty/lk/trusty/+/3178322

Change-Id: I40f94ee044759c43e3c0c28080e346a5c5854d9f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>