UPSTREAM: ASoC: soc-pcm: Move debugfs removal out of spinlock

The recent fix for DPCM locking also covered the loop in
dpcm_be_disconnect() with the FE stream lock.  This caused an
unexpected side effect, thought: calling debugfs_remove_recursive() in
the spinlock may lead to lockdep splats as the code there assumes the
SOFTIRQ-safe context.

For avoiding the problem, this patch changes the disconnection
procedure to two phases: at first, the matching entries are removed
from the linked list, then the resources are freed outside the lock.

Bug: 291825551
Fixes: b7898396 ("ASoC: soc-pcm: Fix and cleanup DPCM locking")
Reported-and-tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Change-Id: I7a793b029cfbddb6082afe001c08890c54c67045
Signed-off-by: Takashi Iwai <tiwai@suse.de>
(cherry picked from commit 9f620684)
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>