Teardown is triggered when the display topology changes and no
long meets the secure playback requirement, and hardware trashes
all the encryption keys for display. Additionally, we want to emit a
teardown operation to make sure we're clean on boot and resume

v2: emit in the ring, use high prio request (Chris)
v3: better defines, stalling flush, cleaned up and renamed submission
    funcs (Chris)
v12: fix uninitialized variable bug
Signed-off-by: NHuang, Sean Z <sean.z.huang@intel.com>
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210924191452.1539378-9-alan.previn.teres.alexis@intel.com