Added support for SWD transport similar to sysfsgpio driver.
Added configurable peripheral base address to support Raspberry Pi 2.
Change-Id: If76d45fbe74ce49f1f22af72e5f246e973237e04
Signed-off-by: Christoph Pittracher <pitt@segfault.info>
Reviewed-on: http://openocd.zylin.com/2802
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>