libmetal.cmake:modify libmetal headers according to Makefile reference

[xuxin930]

Summary

Fix undefined issues in libmetal cmake build

Impact

this patch should fix https://github.com/apache/nuttx/issues/10401 issue

Testing

CI build

[xiaoxiang781216]

@xuxin930 but the ci fail to build.

[raiden00pl]

this patch should fix https://github.com/apache/nuttx/issues/10401 issue

This issue is about broken make build. If we modify cmake to be the same as make - should I assume that cmake will also be broken? :)