ASoC: Intel: Skylake: modify skl_get_dsp_ops()

To query the ops used for a platform, we use skl_get_dsp_ops() which return
index and then we load the ops.

Rather than this return the ops, this way it cna be used later to query the
ops in rest of the driver.

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>