ASoC: arizona: Access driver data through platform from compressed ops

As the compressed ops run on the platform side of things we should
really access the driver data through the platform pointer rather than
the CODEC pointer. As the compressed DAIs in our systems always connect
our CODEC to our platform this has never been an issue, but should still
be corrected. Additionally it clears the way for future core refactoring
work.

Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>