build: add Wstrict-overflow and FORTIFY_SOURCE options

This patch adds further compiler options related to security to
RMM build options. The `-D_FORTIFY_SOURCE=2` is added mainly
for future proofing as RMM does not link against glibc today
but may do so in future.

Change-Id: I711135491a17cd6f11da72e1b6c701c149f017aa
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
1 file changed