kconfig/streamline_config.pl: merge local{mod,yes}config

The two targets `localmodconfig' and `localyesconfig' only differs from the
sed(1) ran on the result of `streamline_config.pl' to convert symbols set to
`modules' to `yes'. This conversion can be made directly from the perl script,
and thus avoid duplicating the command to generate the configuration.

Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>