Add default hostname Kconfig item

components/config/config.c

@@ -33,7 +33,10 @@ typedef struct {
 } Item;
 
 static Item state[ITEM_COUNT] = {
-	[HOSTNAME] = { .id = "hostname", .default_value = "bedside-clock" },
+	[HOSTNAME] = {
+	    .id = "hostname",
+	    .default_value = CONFIG_DEFAULT_HOSTNAME,
+	},
 };
 
 static bool load(ItemIndex item)

main/Kconfig.projbuild

@@ -0,0 +1,6 @@
+menu "Bedside clock settings"
+     config DEFAULT_HOSTNAME
+            string "The default hostname for the device"
+            default "bedside-clock"
+            prompt "Default hostname"
+endmenu