Here the need is for a macro that checks whether the given symbol is
defined or not, which has nothing to do with config.

The new macro __is_defined() is a better fit for this case.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NMichal Marek <mmarek@suse.com>