ASoC: Intel: skl_hda_generic: remove rtd->codec_dai

Use macro and solve compilation issues

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200415032647.11209-1-pierre-louis.bossart@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>