Some classes, as for example nativesdk, defines CPPFLAGS and CXXFLAGS
to be passed to compiler. Using those makes more sense and avoid some
hacks on packages using CMake.
(From OE-Core rev: de60d1d91b28c3f5568b132a8eb29d9a754e68a0)
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>