Revert "hwspinlock: Introduce hwspin_lock_bust()"

This reverts commit 1227a242 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: Iaf3c3ada1531c0d19e2f0825f33e125acbbbfbea
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>