ASoC: Intel: avs: Use helper to setup HOST stream

snd_hdac_ext_host_stream_setup() abstracts the procedure details away.
Simplify the code by using it.

Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20230926080623.43927-4-cezary.rojewski@intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>