The case when "some-arch" is not a valid Linux architecture results in an error.
This makes sense if the TARGET_OS is Linux, but that is not always the case.
kernel-arch is also inherited by toolchain-script, which may be used to build
toolchains for architectures not supported by Linux.
Rather than modifying toolchain-script to provide its own version of "map_arch"
this patch bypasses the error if the TARGET_OS is not linux.
Signed-off-by: Juro Bystricky <juro.bystricky@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
