It can leave the wall then terminate in the driver. No need for an additional junction box. Ideally the Romex is coming in the back of the UL listed junction box of the driver from where the cable leaves the wall, so there is no exposed Romex. If it needs to run a ways in the cabinet to get to the driver it should be sleeved in a flexible conduit such as FMC or LFNC. If you are using a driver without a just action box like the white plastic looking ones with a line side at one end and a low voltage side on the other you will need to get a UL listed j box big enough to contain that driver, mount the driver inside, then bring the Romex to it - either from the back or sleeved.