ASoC: Intel: Skylake: Fix to cleanup if skl_sst_dsp_init fails

This patch fixes the below warning reported by Dan by invoking
skl_sst_dsp_cleanup() in cleanup path on error and not bailing out

	sound/soc/intel/skylake/skl-sst.c:270 skl_sst_dsp_init()
	info: ignoring unreachable code.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>