dt-bindings: display: panel: constrain 'reg' in DSI panels (part two)

DSI-attached devices could respond to more than one virtual channel
number, thus their bindings are supposed to constrain the 'reg' property
to match hardware.  Add missing 'reg' constrain for DSI-attached display
panels, based on DTS sources in Linux kernel (assume all devices take
only one channel number).

Few bindings missed previous fixup: LG SW43408 and Raydium RM69380.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240605105659.27433-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Documentation/devicetree/bindings/display/panel/lg,sw43408.yaml

@@ -21,7 +21,9 @@ properties:
     items:
       - const: lg,sw43408
 
-  reg: true
+  reg:
+    maxItems: 1
+
   port: true
   vddi-supply: true
   vpnl-supply: true

Documentation/devicetree/bindings/display/panel/raydium,rm69380.yaml

@@ -28,6 +28,9 @@ properties:
       to work with the indicated panel. The raydium,rm69380 compatible shall
       always be provided as a fallback.
 
+  reg:
+    maxItems: 1
+
   avdd-supply:
     description: Analog voltage rail
 
@@ -38,8 +41,6 @@ properties:
     maxItems: 1
     description: phandle of gpio for reset line - This should be active low
 
-  reg: true
-
 required:
   - compatible
   - reg