flash: Added support for at91sam4sd32c

Change-Id: I7223980602d7595a3dd7a3ceaac3f58d4f73f88d
Signed-off-by: Peter Dietzsch <peter.dietzsch@ib-dt.de>
Reviewed-on: http://openocd.zylin.com/1332
Tested-by: jenkins
Reviewed-by: Peter Stuge <peter@stuge.se>
cfg: Added cfg script for at91sam4sd32x targets

Change-Id: I3b8a54d89a180bfded3dae3f1fe3d940540e6e7d
Signed-off-by: Peter Dietzsch <peter.dietzsch@ib-dt.de>
Reviewed-on: http://openocd.zylin.com/1333
Tested-by: jenkins
Reviewed-by: Peter Stuge <peter@stuge.se>