My bathroom, inside near door, has a 2-gang box, containing 2 light switches, powering combination ceiling light and fan. This box is fed by hallway lighting circuit, and the work box is not covered by GFCI.

The changes I want to make are:

* Exchange both switches with a "2 horizontal switch" device, freeing up a gang (example: Leviton 5634-W)
* Install a USB-ONLY outlet (example: Leviton USB4P)

My question is whether this change is "to code" (NEC)? I am in Northeast USA (NH).

For completeness: My bathroom electrical outlets ARE on a different circuit, in a different work box, and yes that is protected by GFCI. 

The question is about adding a USB "outlet" to an area that normally requires all outlets to be GFI. My understanding is what I plan would be OK because these are low-voltage.