Fix host build for newer linux distros

I realized there was a better way to do this..

Instead of specifying a path just have gcc run the preprocessor (-E) on
an input file consisting of only '#include <byteswap.h>' if it succeeds
then we can use it if not then don't define OS_USE_BYTESWAP_H

Change-Id: I0de8e469445221bc1b5ad8cc032de5b89a85ab66
1 file changed