dt-bindings: serial: 8250: Add npcm845 compatible string

Add a compatible string for Nuvoton BMC NPCM845 UART.
Signed-off-by: NTomer Maimon <tmaimon77@gmail.com>
Acked-by: NKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220630103606.83261-3-tmaimon77@gmail.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/serial/8250.yaml

@@ -62,6 +62,7 @@ properties:
       - const: mrvl,pxa-uart
       - const: nuvoton,wpcm450-uart
       - const: nuvoton,npcm750-uart
+      - const: nuvoton,npcm845-uart
       - const: nvidia,tegra20-uart
       - const: nxp,lpc3220-uart
       - items: