ASoC: Replace pdev with card in machine driver probe and remove

In order to support cards instantiated without using soc-audio remove
the use of the platform device in the card probe() and remove() ops.

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