spi: pxa2xx: Use newer more explicit DMAengine terminate API

Commit b36f09c3 ("dmaengine: Add transfer termination
synchronization support") marked dmaengine_terminate_all() as
deprecated and is being replaced by explicit synchronous and asynchronous
terminate functions.

Here DMA termination are done in two cases: FIFO overrun and module
removal.

FIFO overrun is handled in interrupt context and converting
dmaengine_terminate_all() to dmaengine_terminate_async() does the same than
before.

Using synchronous termination in module removal however adds a bit more
robustness as it waits all completion callbacks have finished. Although it
looks all known DMA engines used with spi-pxa2xx don't implement
device_synchronize() callback so this too appears to be a no-op in
practice.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>