dt-bindings: crypto: sec-v4.0-mon: add snvs power off support

Add SNVS power off support. The SNVS_LP LPCR register could
drive signal to PMIC to turn off system power.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20230323123907.103719-1-peng.fan@oss.nxp.comSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/crypto/fsl,sec-v4.0-mon.yaml

@@ -113,6 +113,12 @@ properties:
   snvs-lpgpr:
     $ref: /schemas/nvmem/snvs-lpgpr.yaml#
 
+  snvs-poweroff:
+    description:
+      The SNVS could drive signal to PMIC to turn off system power by setting
+      SNVS_LP LPCR register.
+    $ref: /schemas/power/reset/syscon-poweroff.yaml#
+
 required:
   - compatible
   - reg