buildroot

cryptopp: new package

Signed-off-by: Julian Scheel <julian@jusst.de>
[Thomas:
 - put HOST_CRYPTOPP_EXTRACT_CMDS earlier in the file, since it's what
   gets executed first.
 - fix typo in the name of HOST_CRYPTOPP_MAKE_OPTS
 - pass -fPIC in CXXFLAGS, since we're building a shared library
 - just call "make shared" for the build and "make install" for the
   installation.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>