As polling $dbger, call keep_alive() to avoid timeout messages. Change-Id: Ia03d90535c2bd6049763209194c21f70fd8b7e8b Signed-off-by: Hsiangkai Wang <hsiangkai@gmail.com> Reviewed-on: http://openocd.zylin.com/1566 Tested-by: jenkins Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>tags/v0.8.0-rc1