ASoC: kirkwood: Fix reference to PCM buffer address

The transition to the managed PCM buffers allowed the dynamically
buffer allocation, while the driver code still assumes the fixed
preallocation buffer and sets up the DMA stuff at the open call.
This needs to be moved to hw_params after the buffer allocation and
setup.  Also, the reference to the buffer address has to be corrected
to runtime->dma_addr.

Fixes: b3c0ae75

 ("ASoC: kirkwood: Use managed DMA buffer allocation")
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20210728112353.6675-6-tiwai@suse.de
Signed-off-by: Mark Brown <broonie@kernel.org>