lib: smc: Add smc8_ret18/hvc8_ret18 am: 09026ddc2d

Original change: https://android-review.googlesource.com/c/trusty/lk/trusty/+/3505621

Change-Id: I46aafe098eafc76b6f4d91a5911e085ee0df7343
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>