ASoC: soc-core: fix crash when removing not instantiated card

If the card was not instantiated in snd_soc_instantiate_card, calling
soc-remove will crash because some of codec, cpu_dai and card .remove
methods are called twice.
Fix this by returning from soc_remove immediately.

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>