ata: sata_dwc_460ex: switch to new dmaengine_terminate_* API

Convert dmaengine_terminate_all() calls to synchronous and asynchronous
versions where appropriate.

Tested-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>