ASoC: Intel: Skylake: code cleanup for pin fixup limitation

As a commit 4cd9899f ("ASoC: Intel: Skylake: Add multiple pin
formats") describes, 'fixups is applied to pin 0 only'. On the other
hand, the commit left some codes as what they were. This might
confuses readers.

This commit fixes the issue. This doesn't change driver behaviour at all.

Fixes: 4cd9899f ("ASoC: Intel: Skylake: Add multiple pin formats")
Signed-off-by: Takashi Sakamoto <takashi.sakamoto@miraclelinux.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Tested-by: Subhransu S. Prusty <subhransu.s.prusty@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>