Add missing virtual destructors to some base class

rpcs3/Emu/Io/PadHandler.h

@@ -15,6 +15,7 @@
 class PadDevice
 {
 public:
+	virtual ~PadDevice() = default;
 	cfg_pad* config{ nullptr };
 	u8 player_id{0};
 };

rpcs3/Emu/Io/usb_device.h

@@ -167,6 +167,7 @@ class usb_device
 {
 public:
 	usb_device(const std::array<u8, 7>& location);
+	virtual ~usb_device() = default;
 
 	virtual bool open_device() = 0;