add portability fixes for toolchain/tools (full tools/toolchain build works on osx now)
git-svn-id: svn://svn.openwrt.org/openwrt/branches/buildroot-ng/openwrt@4867 3c298f89-4303-0410-b956-a3cf2f4a3e73
- [DH] tools/include/byteswap.h
- [DH] tools/include/endian.h
- [DH] tools/include/getline.h