ASoC: Intel: Convert skl machine data to C99 style

C99 style struct initialization helps in readability as well as
initialization of variables not specified as NULL.
Patch modifies all skl machine data.

Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Naveen M <naveen.m@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>