Revert "ASoC: soc-pcm: serialize BE triggers"

This reverts commit 2cf8c9f8 which is
commit b2ae8066 upstream.

It is part of a series of ASoC patches that break the Android abi.  If
they are needed in the future they can be brought back in an ABI-safe
way.

Bug: 161946584
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I0525b7f140835d518936c3d4d16eb6f950426cac