xen/dt: ifdef out DEV_DT-related bits from device_tree.{c,h}

Architectures that don't discover devices via DT may skip anything to
do with device_t during the DT unflattening phase. Make device-tree.c
stop requiring CONFIG_HAS_DEVICE_TREE_DISCOVERY so it may function with
CONFIG_DEVICE_TREE_PARSE alone.

This allows CONFIG_DEVICE_TREE_PARSE to unflatten a DT ignoring its
devices if CONFIG_HAS_DEVICE_TREE_DISCOVERY is not selected.

Signed-off-by: Alejandro Vallejo <alejandro.garciavallejo@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

xen/common/device-tree/device-tree.c

@@ -2030,9 +2030,11 @@ static unsigned long unflatten_dt_node(const void *fdt,
             ((char *)pp->value)[sz - 1] = 0;
             dt_dprintk("fixed up name for %s -> %s\n", pathp,
                        (char *)pp->value);
+#ifdef CONFIG_HAS_DEVICE_TREE_DISCOVERY
             /* Generic device initialization */
             np->dev.type = DEV_DT;
             np->dev.of_node = np;
+#endif /* CONFIG_HAS_DEVICE_TREE_DISCOVERY */
         }
     }
     if ( allnextpp )

xen/include/xen/device_tree.h

@@ -108,9 +108,12 @@ struct dt_device_node {
      */
     struct list_head domain_list;
 
+#ifdef CONFIG_HAS_DEVICE_TREE_DISCOVERY
     struct device dev;
+#endif /* CONFIG_HAS_DEVICE_TREE_DISCOVERY */
 };
 
+#ifdef CONFIG_HAS_DEVICE_TREE_DISCOVERY
 #define dt_to_dev(dt_node)  (&(dt_node)->dev)
 
 static inline struct dt_device_node *dev_to_dt(struct device *dev)
@@ -119,6 +122,7 @@ static inline struct dt_device_node *dev_to_dt(struct device *dev)
 
     return container_of(dev, struct dt_device_node, dev);
 }
+#endif /* CONFIG_HAS_DEVICE_TREE_DISCOVERY */
 
 #define MAX_PHANDLE_ARGS 16
 struct dt_phandle_args {