Refactor routing

Patch init to simplify routing. Update Dhall library and NixOS modules
accordingly.

nixos-modules/genode-init.nix

@@ -4,15 +4,6 @@ with lib;
 
 let
   cfg = config.genode.init;
-  coreROMs = mkOption {
-    type = with types; listOf str;
-    default = [ ];
-    description = ''
-      List of label suffixes that when matched against
-      ROM requests shall be forwared to the core.
-    '';
-    example = [ "platform_info" ];
-  };
   inputs = mkOption {
     description = "List of packages to build a ROM store with.";
     default = [ ];
@@ -56,7 +47,7 @@ in {
       type = with types;
         attrsOf (submodule {
           options = {
-            inherit coreROMs inputs;
+            inherit inputs;
             configFile = mkOption {
               type = types.path;
               description = ''
@@ -64,6 +55,15 @@ in {
                 See https://git.sr.ht/~ehmry/dhall-genode/tree/master/Init/Child/Type
               '';
             };
+            coreROMs = mkOption {
+              type = with types; listOf str;
+              default = [ ];
+              description = ''
+                List of label suffixes that when matched against
+                ROM requests shall be forwared to the core.
+              '';
+              example = [ "platform_info" ];
+            };
           };
         });
     };
@@ -76,7 +76,7 @@ in {
         type = with types;
           attrsOf (submodule {
             options = {
-              inherit coreROMs inputs;
+              inherit inputs;
               configFile = mkOption {
                 type = types.path;
                 description = ''