cfg: ignore ICEPick jrc tap version

Due to reports of newer targets using a updated version of the ICEPick tap
rather than add another tapid we ignore the tap version.

Also see Trac 49 for details.

Change-Id: Ic78414c54af2545c817e1bb2c860970c1b587259
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/1373
Tested-by: jenkins
Reviewed-by: Peter Stuge <peter@stuge.se>