getarch/cpuid.S: Fix warning about executable stack

When using the GNU toolchain a warning is printed about an executible
stack:
 /usr/lib64/gcc/.../x86_64-suse-linux/bin/ld: warning: /tmp/ccyG3xBB.o: missing .note.GNU-stack section implies executable stack
[   15s] /usr/lib64/gcc/.../x86_64-suse-linux/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
to prevent this warning, add:
    ```
            .section        .note.GNU-stack,"",@progbits
    ```

Signed-off-by: Egbert Eich <eich@suse.com>

cpuid.S

@@ -65,3 +65,6 @@ _cpuid:
 	.subsections_via_symbols
 
 #endif
+#if defined(__ELF__) && defined(__linux__)
+        .section        .note.GNU-stack,"",@progbits
+#endif