I'm GUESSING that the cable is all you need.
On the PS3 set up, the RCA jacks used the PS3 AV out for game sound (I pretty sure the third jack with the line through it [i.e. do not use] is the video jack) and the video goes through the HDMI cable
I'm GUESSING that in the PS4 the game audio and video is now reliant on the HDMI cable, which is not shown, but is actually there when you set it up.
I'm GUESSING the PS4 doesn't come with a separate analogue AV outlet like the PS3 does so, as it is only digital, the only way to get sound back to the PX3 headset is to use the RCA outlets on your TV as the PX3 box doesn't show a digital input (in the diagram)
That just leaves the chat which is what the mobile lead is for.
Like I say this is all guess work as I haven't had a chance to look around for the PS4 spec but that would be my guess - hope it helps