dmaengine: xilinx: xdma: Add terminate_all/synchronize callbacks

The driver is capable of starting scatter-gather transfers and needs to
wait until their end. It is also capable of starting cyclic transfers
and will only be "reset" next time the channel will be reused. In
practice most of the time we hear no audio glitch because the sound card
stops the flow on its side so the DMA transfers are just
discarded. There are however some cases (when playing a bit with a
number of frames and with a discontinuous sound file) when the sound
card seems to be slightly too slow at stopping the flow, leading to a
glitch that can be heard.

In all cases, we need to earn better control of the DMA engine and
adding proper ->device_terminate_all() and ->device_synchronize()
callbacks feels totally relevant. With these two callbacks, no glitch
can be heard anymore.

Fixes: cd8c732c

 ("dmaengine: xilinx: xdma: Support cyclic transfers")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://lore.kernel.org/r/20231130111315.729430-5-miquel.raynal@bootlin.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>