Add motherboard asset model and repository; hide specific properties in overview

src/main/java/be/seeseepuff/pcinv/models/RamAsset.java

@@ -34,4 +34,8 @@ public class RamAsset implements Asset
 	@Property("Type")
 	@InputList
 	private String type;
+
+	@Description("The speed of the memory in MHz.")
+	@Property("Speed")
+	private Long speed;
 }