It isn’t worth it to make that display work on a hikey960. It may be marginally useful on boards that support multiple displays, like dragonboard 820c, but these (hikey/960) only have a single display interface. You can use that interface either for a DSI panel, or through the DSI-to-HDMI converter to run an HDMI display.
What you’re up against here, is essentially designing, printing, and assembling your own custom circuit board… and then writing all the software needed to bring up your particular panel. There is a HUGE amount of work to do there, that you can skip over entirely just by selecting an HDMI display.
Lets look at it from the basis of the value of your time. If your time is only worth $5 an hour, then THIS panel (https://www.chalk-elec.com/?page_id=1283#!/7-black-frame-universal-HDMI-LCD-with-capacitive-multi-touch/p/21750201/category=3094861) has a value of 25 hours of your time.
I promise you that you will NOT get that pi panel working in just 25 hours. And to top that off, that pi panel is a junk panel – only 800x480, whereas the one I linked to is 1280x800. Shop around on ebay, and you even find better deals on better panels (like the high brightness version of that panel hsd070pww1-c00 – 690 nits).