dt-bindings: crypto: fsl,sec-v4.0-mon: Add "linux,keycodes" and deprecate "linux,keycode"

The "linux,keycode" property is non-standard. Add the common property
"linux,keycodes" and mark "linux,keycode" deprecated so that the mistake
is not propagated.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230613201231.2826352-2-robh@kernel.org


Signed-off-by: Rob Herring <robh@kernel.org>