drm/pl111: Deprecate the pads from the DT binding

The pads were an earlier workaround for the internal image
pipeline in the Linux fbdev subsystem. As we move to generic
definition of display properties and drivers that no longer
need this to work, deprecate this property.

Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Liviu Dudau <Liviu.Dudau@arm.com>
Cc: devicetree@vger.kernel.org
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190724134959.2365-1-linus.walleij@linaro.org

Documentation/devicetree/bindings/display/arm,pl11x.txt

@@ -39,9 +39,11 @@ Required sub-nodes:
 
 - port: describes LCD panel signals, following the common binding
 	for video transmitter interfaces; see
-	Documentation/devicetree/bindings/media/video-interfaces.txt;
-	when it is a TFT panel, the port's endpoint must define the
-	following property:
+	Documentation/devicetree/bindings/media/video-interfaces.txt
+
+Deprecated properties:
+	The port's endbpoint subnode had this, now deprecated property
+	in the past. Drivers should be able to survive without it:
 
 	- arm,pl11x,tft-r0g0b0-pads: an array of three 32-bit values,
 		defining the way CLD pads are wired up; first value
@@ -80,7 +82,6 @@ Example:
 		port {
 			clcd_pads: endpoint {
 				remote-endpoint = <&clcd_panel>;
-				arm,pl11x,tft-r0g0b0-pads = <0 8 16>;
 			};
 		};