zip: fix configure check by using _Static_assert

It's incorrect to run a cross-compiled program on build machine
to check if some feature is available or not. As these two checks
in zip are basically just checking the size, we can use _Static_assert
and sizeof to do such check at compile time.

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>