ASoC: dmaengine_pcm: Add port_window_size to DAI dma data struct

ASoC: dmaengine_pcm: Add port_window_size to DAI dma data struct

The port_window_size is a struct member of dma slave channel runtime
config. It's the length of the register area in words the data need to
be accessed on the device side. It is only used for devices which is
using an area instead of a single register to send or receive the data.
Typically the DMA loops in this area in order to transfer the data.

It's useful for cases that reading/writing multiple registers in DMA
transactions.

Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
Link: https://patch.msgid.link/20250808061741.187414-1-chancel.liu@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>