armv7a: correctly handle invalidation of inner data caches

armv7a: correctly handle invalidation of inner data caches

D-Cache invalidate is a dangerous operation. It will only work correctly
if full cache lines are invalidated. When partial cache lines are
invalidated, i.e. the target address range does not start and end
at a cache line boundary, cpu data writes outside of the target range
will be dropped. This patch adds special treatment for partial cache
lines by doing a clean & invalidate on the partial lines before
invalidating the rest of the range.

Change-Id: I64099ddb058638e990a7eb0ee911b9cc8f6f8901
Signed-off-by: Matthias Welwarsky <matthias@welwarsky.de>
Reviewed-on: http://openocd.zylin.com/3034
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>