The code loading for Skylake and other platforms is different, so
add a dsp_ops and a loader_ops which can be defined for each
platform.

Move the dsp init, cleanup and loader ops (alloc and free dma) to
these ops
Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>