intel_sst: return correct output/input device id

Without this patch, the change of output/input device can't be reflected
correctly. The mismatch reflects insane design, and should be fixed when
switching to the ASoC framework.

Signed-off-by: Lu Guanqun <guanqun.lu@intel.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>