libc: Introduce files from SCC

Taken from http://git.simple-cc.org/scc/

 from the following commit:

67508ad14af314cea2229783d3c084f28c41daf0

Permission has been granted from the author to use them under the
license BSD-3-Clause instead of ISC.

Change-Id: I65c0ce3ab60c49d34a57533af12a74bd7bde88e5
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>