Add -flto to CXXFLAGS

Per openbmc/openbmc#3364, adding -flto to CXX flags
in order to reduce overall library and binary sizes.

Ref: https://gcc.gnu.org/wiki/LinkTimeOptimization

Change-Id: I3ee31a15fc0ded4308aa9d00a11b41bc62eb9799
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
5 files changed