The recommended HDA HW programming sequence for setting
the DMA format requires that the link DMA and host DMA
channels be coupled before setting the format. This
change means that host DMA or link DMA channels be
reserved even if only one is used.

Statically assigned link DMA channels would mean that
all the corresponding host DMA channels will need to be
reserved, leaving only a few channels available at run-time.
So, the suggestion here is to switch to dynamically assigning
both host DMA channels and link DMA channels are run-time.

This change means that the DAI_CONFIG IPC will be sent
multiple times during link hw_params and link hw_free
ioctl. The DAI config parameters will remain the same
except for the link DMA channel that will be assigned at
run-time. A value of DMA_CHAN_INVALID from the driver
during hw_free indicates a request to free the current
link DMA channel in use. The current channel in use
is freed before assiging the new channel requested in
the DAI_CONFIG IPC.

Signed-off-by: Ranjani Sridharan <[email protected]>