GLib 2.60 onwards checks for /proc/self/cmdline instead of assuming that
it exists on Linux (because Cygwin also has it). As this is a runtime
test it doesn't execute in cross builds so defaults to false, but under
Linux this should be true.
Restore the previous behaviour and silence the warning by setting the
cross property appropriately.
Signed-off-by: Ross Burton <ross.burton@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
