ASoC: mpc5200_dma: Don't overwrite ac97 device private_data

ASoC: mpc5200_dma: Don't overwrite ac97 device private_data

The mpc5200_dma overwrites the private_data field of the CODEC's AC'97
device with the DMA drivers private data, but never actually reads it again.
Given that the private_data field is supposed to be owned by the AC'97
driver, overwriting it may cause undefined behavior. This patch removes the
code that overwrites the field from the driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>