Hyundai CAN FD: fix safety tx and rx struct names

Can you tell what these two are for? Do they include longitudinal actuation messages or not?

```
static const CanMsg HYUNDAI_CANFD_LFA_STEERING_LONG_TX_MSGS[] = {
...

#define HYUNDAI_CANFD_LFA_STEERING_CAMERA_SCC_TX_MSGS(longitudinal) \
...
```

Hint

First should make it clear it's a radar SCC car. Second should make it clear it also includes longitudinal actuation messages.