yocto/safety_island: Ensure all regexes have termination characters

Regexes that end in unbounded pattern matches (e.g. \d+) are problematic
with pexpect because they may match fewer characters than expected,
depending on the performance of the test host.

To fix this, ensure that all regex are terminated with one or more
explicit characters (e.g. \r\n).

Issue-Id: SCM-5314
Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
Change-Id: I5038510392c81614fef82ecf5e8777f060ff315f