dt-bindings: arm: Add i.MX8M Plus Gateworks GW74xx board

Add DT compatible string for i.MX8M Plus based Gateworks GW74xx board.
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Documentation/devicetree/bindings/arm/fsl.yaml

@@ -903,6 +903,7 @@ properties:
         items:
           - enum:
               - fsl,imx8mp-evk            # i.MX8MP EVK Board
+              - gateworks,imx8mp-gw74xx   # i.MX8MP Gateworks Board
               - toradex,verdin-imx8mp     # Verdin iMX8M Plus Modules
               - toradex,verdin-imx8mp-nonwifi  # Verdin iMX8M Plus Modules without Wi-Fi / BT
               - toradex,verdin-imx8mp-wifi  # Verdin iMX8M Plus Wi-Fi / BT Modules