boot/atari_m68k: Handle should be a subclass of Node

hrev55571 introduced several new pure virtual functions in Node,
none of which are implemented in Handle or any of its descendants.

This change fixes the build after the Node/ConsoleNode refactor.

Change-Id: I825b90a114d83105f46d566e7fe1f644ba997ec5
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6939
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

src/system/boot/platform/atari_m68k/Handle.h

@@ -12,7 +12,7 @@
 
 #ifdef __cplusplus
 
-class Handle : public ConsoleNode {
+class Handle : public Node {
 	public:
 		Handle(int handle);
 		Handle();