ASoC: Remove unneeded suspend checks from CODEC drivers

Better integration of the core with the device model means that we now
no longer get the ASoC suspend and resume callbacks without the card
having been set up.

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