dt-bindings: serial: fsl-lpuart: add i.MXRT1170 compatible

Add i.MXRT1170 compatible string to Documentation.

Cc: Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Jesse Taube <Mr.Bossman075@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20221107071511.2764628-5-Mr.Bossman075@gmail.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/serial/fsl-lpuart.yaml

@@ -32,6 +32,9 @@ properties:
               - fsl,imx8qm-lpuart
               - fsl,imx8dxl-lpuart
           - const: fsl,imx8qxp-lpuart
+      - items:
+          - const: fsl,imxrt1050-lpuart
+          - const: fsl,imxrt1170-lpuart
 
   reg:
     maxItems: 1