dt-bindings: display: panel: sitronix,st7701: Add Densitron DMT028VGHMCMI-1A TFT

Add compatible string for Densitron DMT028VGHMCMI-1A TFT matrix.
This is a DSI-attached 480x640 2.83 inch panel.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Guido Günther <agx@sigxcpu.org>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: devicetree@vger.kernel.org
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220725151703.319939-1-marex@denx.de

Documentation/devicetree/bindings/display/panel/sitronix,st7701.yaml

@@ -17,6 +17,9 @@ description: |
   Techstar TS8550B is 480x854, 2-lane MIPI DSI LCD panel which has
   inbuilt ST7701 chip.
 
+  Densitron DMT028VGHMCMI-1A is 480x640, 2-lane MIPI DSI LCD panel
+  which has built-in ST7701 chip.
+
 allOf:
   - $ref: panel-common.yaml#
 
@@ -24,6 +27,7 @@ properties:
   compatible:
     items:
       - enum:
+          - densitron,dmt028vghmcmi-1a
           - techstar,ts8550b
       - const: sitronix,st7701