ViaMichelin estimates the driving time Seville-Ronda-Ardales-Granada at over 4-1/2 hours. That's with no stops, getting lost, looking for parking in Ronda or walking from where you park in Ronda to the edge of the historic area (I don't know how far that will be). Even dropping Ardales, it's still a 4-1/2 hour drive. Either of those stops would take a good bit of time, plus you have to find food at least once during the day. I think you have time for one stop but trying to do both of them would be pushing it.
The Caminito del Rey website mentions a walking time of 3 to 4 hours, but I'm not clear on transport back to the parking lot you would need to use. Are there buses all the time? If so, how often do they run? Also, if this is an end-of-year trip, note that the Caminito is closed on December 24, 25, 30 and 31 as well as on January 1. The December 30 closure is because it's a Monday.