Implement controller gyroscope in SDL

include/services/hid.hpp

@@ -88,6 +88,8 @@ class HIDService {
 	}
 
   public:
+	static constexpr float gyroscopeCoeff = 14.375f;  // Same as retail 3DS
+
 	HIDService(Memory& mem, Kernel& kernel) : mem(mem), kernel(kernel) {}
 	void reset();
 	void handleSyncRequest(u32 messagePointer);