As GDB uses file-I/O protocol to access memory, use DMA to access
if no DCache. This commit improves the performance of Andes
Virtual Hosting.
Change-Id: I36bb2154b9f497fc4237625836cf8c7115330a60
Signed-off-by: Hsiangkai Wang <hsiangkai@gmail.com>
Reviewed-on: http://openocd.zylin.com/1580
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>