soundwire: intel_ace2x: release bpt_stream when close it

soundwire: intel_ace2x: release bpt_stream when close it

The BPT stream was allocated in intel_ace2x_bpt_open_stream(), we need
to free it in intel_ace2x_bpt_close_stream().

Fixes: 4c1ce9f37d8a8 ("soundwire: intel_ace2x: add BPT send_async/wait callbacks")
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Simon Trimmer <simont@opensource.cirrus.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Link: https://patch.msgid.link/20260514141625.1834216-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>