make-mod-scripts: change how some kernel module tools are built
Remove do_make_scripts() from module-base.bbclass and put
functionality in a recipe. This will build the scripts only
once instead of each time an external module is built.
[YOCTO #12228]
Signed-off-by: Joe Slater <jslater@windriver.com> Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>