xen/docs: arm: Update dom0less binding and example

The binding for the dom0less module does not match Xen implementation.
Any module should contain the compatible "multiboot,module" to be
recognized.

This was clearly an oversight as other examples with Xen code base
provide the compatible "multiboot,module".

So fix the binding and the example associated to it.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Release-acked-by: Juergen Gross <jgross@suse.com>

docs/misc/arm/device-tree/booting.txt

@@ -171,7 +171,7 @@ The kernel sub-node has the following properties:
 
 - compatible
 
-    "multiboot,kernel"
+    "multiboot,kernel", "multiboot,module"
 
 - reg
 
@@ -186,7 +186,7 @@ The ramdisk sub-node has the following properties:
 
 - compatible
 
-    "multiboot,ramdisk"
+    "multiboot,ramdisk", "multiboot,module"
 
 - reg
 
@@ -207,13 +207,13 @@ chosen {
         vpl011;
 
         module@0x4a000000 {
-            compatible = "multiboot,kernel";
+            compatible = "multiboot,kernel", "multiboot,module";
             reg = <0x0 0x4a000000 0xffffff>;
             bootargs = "console=ttyAMA0 init=/bin/sh";
         };
 
         module@0x4b000000 {
-            compatible = "multiboot,ramdisk";
+            compatible = "multiboot,ramdisk", "multiboot,module";
             reg = <0x0 0x4b000000 0xffffff>;
         };
     };
@@ -226,13 +226,13 @@ chosen {
         cpus = <1>;
 
         module@0x4c000000 {
-            compatible = "multiboot,kernel";
+            compatible = "multiboot,kernel", "multiboot,module";
             reg = <0x0 0x4c000000 0xffffff>;
             bootargs = "console=ttyAMA0 init=/bin/sh";
         };
 
         module@0x4d000000 {
-            compatible = "multiboot,ramdisk";
+            compatible = "multiboot,ramdisk", "multiboot,module";
             reg = <0x0 0x4d000000 0xffffff>;
         };
     };