Kernel: Move HIDDevice::enable_interrupts method to I8042Device class

It happens to be that only PS/2 devices that are connected via the i8042
controller can generate interrupt events, so it makes much more sense to
have those devices to implement the enable_interrupts method because of
the I8042Device class and not the HIDDevice class.

Kernel/Devices/HID/Device.h

@@ -20,7 +20,6 @@ public:
     };
 
     virtual Type instrument_type() const = 0;
-    virtual void enable_interrupts() = 0;
 
 protected:
     HIDDevice(MajorNumber major, MinorNumber minor)