video: fb: vt8500: Convert framebuffer drivers to standardized binding

Now that a display timing binding is available, convert our almost identical
binding to use the standard binding.

This patch converts the vt8500 and wm8505 framebuffer drivers and
associated dts/dtsi files to use the standard binding as defined in
bindings/video/display-timing.txt.

There are two side-effects of making this conversion:

1) The fb node should now be in the board file, rather than the soc file as
the display-timing node is a child of the fb node.

2) We still require a bits per pixel property to initialize the framebuffer
for the different lcd panels. Rather than including this as part of the
display timing, it is moved into the framebuffer node.

I have also taken the opportunity to alphabetise the includes of each
driver to avoid double-ups.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

arch/arm/boot/dts/wm8850.dtsi

@@ -135,11 +135,9 @@
 			};
 		};
 
-		fb@d8051700 {
+		fb: fb@d8051700 {
 			compatible = "wm,wm8505-fb";
 			reg = <0xd8051700 0x200>;
-			display = <&display>;
-			default-mode = <&mode0>;
 		};
 
 		ge_rops@d8050400 {