Revert "hwspinlock: Introduce hwspin_lock_bust()"

This reverts commit 2da121e3 which is
commit 7c327d56 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I3b8fbd61da08387984c7fbc0d670177d4e1ea62b
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>