ASoC: Intel: Skylake: Update DSP stall bits

The stall bits needs to comprehend the number of DSP cores
running, so update the stall and unstall register writes to
comprehend SKL_DSP_CORES_MASK values as well.

Signed-off-by: Jayachandran B <jayachandran.b@intel.com>
Signed-off-by: Ramesh Babu <ramesh.babu@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>