Add test for Errata management firmware interface.

Add test to check the em_cpu_erratum_features for
a multiprocessor system.

Signed-off-by: Sona Mathew <sonarebecca.mathew@arm.com>
Change-Id: Id09fdb837f44fff63c5ca4249accbca046cc06ef
(cherry picked from commit c28a8dbfb2cda1e4f7f54b1aae51b77990b79ad8)
2 files changed