kconfig: make localmodconfig to run streamline_config.pl

Running the streamline_config.pl script manually can still be confusing
for some users. This patch adds the localmodconfig option. This will
automatically run streamline_config.pl on the current .config and
then run "make silentoldconfig" to fix any wholes that might have been
created.

 $ make localmodconfig

This will remove any module configurations in .config that are not needed
to compile the modules that are loaded.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>