ASoC: xilinx: Fix reference to PCM buffer address

ASoC: xilinx: Fix reference to PCM buffer address

PCM buffers might be allocated dynamically when the buffer
preallocation failed or a larger buffer is requested, and it's not
guaranteed that substream->dma_buffer points to the actually used
buffer.  The driver needs to refer to substream->runtime->dma_addr
instead for the buffer address.

Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20210728112353.6675-4-tiwai@suse.de
Signed-off-by: Mark Brown <broonie@kernel.org>