Revert "[libc-trusty] Add libc wrapper for register_app and unregister_app syscall"

This reverts commit 4517cbf2c6428c7f65ba3a6991bf3dd61f1a5361.
Bug: 130560272

Change-Id: I66cdc8bff380267ac71391a5b85d876e227eba8a
3 files changed