We need to expand SELECTED_OPTIMIZATION later, so
do not immediate expansion, and do the work in
anonymous python function.
It is reasonable to give an error for -O0.
[YOCTO #7058]
(From OE-Core rev: 6fef0d528158e6317793b1ebfa26a7b5413c3e80)
Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>