ASoC: Intel: Skylake: Use num_core to allocate instead of macro

For different platforms, number of dsp cores can vary. So instead of
creating array of size SKL_DSP_CORES_MAX, use num_core in dsp_ops() of
the respective platform to allocate core usage counts and states.

Signed-off-by: Guneshwor Singh <guneshwor.o.singh@intel.com>
Acked-By: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>