ASoC: intel: Kill BUG_ON() usage

Don't use BUG_ON() for a non-critical sanity check on production
systems.  This patch either removes useless BUG_ON() calls.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-By: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>