You don’t need to mount/bind anything.
Kodi always looks in /storage/.kodi/userdata/disp_cap first, if it doesn’t exist then it will look in /sys/class/…
Just doing cat /sys/class/amhdmitx/amhdmitx0/disp_cap > /storage/.kodi/userdata/disp_cap and then editing /storage/.kodi/userdata/disp_cap is sufficient.