ASoC: topology: unload physical dai link in remove

soc_tplg_link_config() will find the physical dai link and call
soc_tplg_dai_link_load() to load the BE dai link. Currently remove_link()
is only used to remove the FE dai link which is created by the topology.
The BE dai link cannot however be unloaded in snd_soc_tplg_component
_remove(), which is problematic if anything needs to be released or
reinitialized.

This patch aligns the definitions of dynamic types with the existing
UAPI and adds a new remove_backend_link() routine to unload the the BE
dai link when snd_soc_tplg_component_remove() is invoked.

Signed-off-by: Bard liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>