ASoC: soc-cache: Ensure flat compression uses a copy of the defaults cache

With the addition of the cache fallback functionality, it is necessary
to ensure that if the register defaults cache was marked as __devinitconst
and the LZO compression is not compiled in the kernel, the fallback to
flat compression will still use a copy of the defaults cache.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>