dt-bindings: lcdif: Add compatible for i.MX8MP

Add compatible string for i.MX8MP LCDIF variant. This is called LCDIFv3
and is completely different from the LCDIFv3 found in i.MX23 in that it
has a completely scrambled register layout compared to all previous LCDIF
variants. The new LCDIFv3 also supports 36bit address space. However,
except for the complete bit reshuffling, this is still LCDIF and it still
works like one.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexander Stein <alexander.stein@ew.tq-group.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Robby Cai <robby.cai@nxp.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stefan Agner <stefan@agner.ch>
Cc: devicetree@vger.kernel.org
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220628174152.167284-1-marex@denx.de

Author: Marek Vasut

Documentation/devicetree/bindings/display/fsl,lcdif.yaml

@@ -20,6 +20,7 @@ properties:
           - fsl,imx23-lcdif
           - fsl,imx28-lcdif
           - fsl,imx6sx-lcdif
+          - fsl,imx8mp-lcdif
       - items:
           - enum:
               - fsl,imx6sl-lcdif