arm64: dts: qcom: sc7180-trogdor: Move panel under the bridge chip

Putting the panel under the bridge chip (under the aux-bus node)
allows the panel driver to get access to the DP AUX bus, enabling all
sorts of fabulous new features.

While we're at this, get rid of a level of hierarchy for the panel
node. It doesn't need "ports / port" and can just have a "port" child.

For Linux, this patch has a hard requirement on the patches adding DP
AUX bus support to the ti-sn65dsi86 bridge chip driver. See the patch
("drm/bridge: ti-sn65dsi86: Add support for the DP AUX bus").
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210611101711.v10.11.Ibdb7735fb1844561b902252215a69526a14f9abd@changeid

arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi

@@ -260,21 +260,6 @@ max98357a: audio-codec-0 {
 		#sound-dai-cells = <0>;
 	};
 
-	panel: panel {
-		/* Compatible will be filled in per-board */
-		power-supply = <&pp3300_dx_edp>;
-		backlight = <&backlight>;
-		hpd-gpios = <&sn65dsi86_bridge 2 GPIO_ACTIVE_HIGH>;
-
-		ports {
-			port {
-				panel_in_edp: endpoint {
-					remote-endpoint = <&sn65dsi86_out>;
-				};
-			};
-		};
-	};
-
 	pwmleds {
 		compatible = "pwm-leds";
 		keyboard_backlight: keyboard-backlight {
@@ -674,6 +659,21 @@ sn65dsi86_out: endpoint {
 				};
 			};
 		};
+
+		aux-bus {
+			panel: panel {
+				/* Compatible will be filled in per-board */
+				power-supply = <&pp3300_dx_edp>;
+				backlight = <&backlight>;
+				hpd-gpios = <&sn65dsi86_bridge 2 GPIO_ACTIVE_HIGH>;
+
+				port {
+					panel_in_edp: endpoint {
+						remote-endpoint = <&sn65dsi86_out>;
+					};
+				};
+			};
+		};
 	};
 };