dt-bindings: display: renesas,du: Document r8a774e1 bindings

Document the RZ/G2H (a.k.a. r8a774e1) SoC in the R-Car DU bindings.
Signed-off-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@bp.renesas.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Documentation/devicetree/bindings/display/renesas,du.txt

@@ -11,6 +11,7 @@ Required Properties:
     - "renesas,du-r8a774a1" for R8A774A1 (RZ/G2M) compatible DU
     - "renesas,du-r8a774b1" for R8A774B1 (RZ/G2N) compatible DU
     - "renesas,du-r8a774c0" for R8A774C0 (RZ/G2E) compatible DU
+    - "renesas,du-r8a774e1" for R8A774E1 (RZ/G2H) compatible DU
     - "renesas,du-r8a7779" for R8A7779 (R-Car H1) compatible DU
     - "renesas,du-r8a7790" for R8A7790 (R-Car H2) compatible DU
     - "renesas,du-r8a7791" for R8A7791 (R-Car M2-W) compatible DU
@@ -77,6 +78,7 @@ corresponding to each DU output.
  R8A774A1 (RZ/G2M)      DPAD 0         HDMI 0         LVDS 0         -
  R8A774B1 (RZ/G2N)      DPAD 0         HDMI 0         LVDS 0         -
  R8A774C0 (RZ/G2E)      DPAD 0         LVDS 0         LVDS 1         -
+ R8A774E1 (RZ/G2H)      DPAD 0         HDMI 0         LVDS 0         -
  R8A7779 (R-Car H1)     DPAD 0         DPAD 1         -              -
  R8A7790 (R-Car H2)     DPAD 0         LVDS 0         LVDS 1         -
  R8A7791 (R-Car M2-W)   DPAD 0         LVDS 0         -              -