dt-bindings: Add resets to the PL011 bindings

Some PL011 implementations provide a reset line to the silicon
IP block, add a device tree property for this.

Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20211120011418.2630449-1-linus.walleij@linaro.orgSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/serial/pl011.yaml

@@ -91,6 +91,9 @@ properties:
       3000ms.
     default: 3000
 
+  resets:
+    maxItems: 1
+
 required:
   - compatible
   - reg