In hindsight it was a very bad idea to use the same refcount for
Extended and 'legacy' HDaudio multi-links. The existing solution only
powers-up the first sublink, which causes SoundWire and SSP tests to
fail when more than one DAI is used concurrently. Solving this problem
requires per-sublink refcounting, as suggested in this patch.

The existing refcounting remains for 'legacy' HdAudio links, mainly to
avoid changing the obscure programming sequence in
snd_hdac_ext_bus_link_put().

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com
Link: https://lore.kernel.org/r/20230512174611.84372-2-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org