CppCheck: Suppress relative path of QCBOR

QCBOR source code is moved into build folder. Its path matched by
CppCheck is relative "lib/ext/qcbor-src".

Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
Change-Id: Ia8eb12d7f125c7f5050eec6a4cf4c54387f1574d
1 file changed