ALSA/ASoC: hda: ext: add 'ext' prefix to snd_hdac_link_free_all

No functionality change, just prefix addition to clearly identify that
the helper only applies to the 'ext' part for Intel platforms.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20221019162115.185917-6-pierre-louis.bossart@linux.intel.com


Signed-off-by: Takashi Iwai <tiwai@suse.de>