build: fix make dist

add missing files to distribution after previous commit.

Change-Id: I0e4b278c090c71d15dd059b6755c9821427cc8ab
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/332


Tested-by: jenkins
Reviewed-by: Mathias Küster <kesmtp@freenet.de>