bring a minimal buildroot kernel modules example to life

More importantly, to make modules_install on the Linux kernel build.

build-linux

@@ -121,6 +121,19 @@ Configure the kernel, but don't build it.
                 ),
                 **common_args
             )
+            common.run_cmd(
+                (
+                    common_make_args +
+                    [
+                        'INSTALL_MOD_PATH={}'.format(common.out_rootfs_overlay_dir), common.Newline,
+                        'modules_install', common.Newline,
+                    ]
+                ),
+                **common_args
+            )
+            # TODO: remove build and source https://stackoverflow.com/questions/13578618/what-does-build-and-source-link-do-in-lib-modules-kernel-version
+            # TODO Basically all kernel modules also basically leak full host paths. Just terrible. Buildroot deals with that stuff nicely for us.
+            # common.rmrf()
 
     def get_argparse_args(self):
         return {