Follow the directions in the repo below:
The secure world console defaults to the same as the normal world since these are just development boards, so you only need one uart cable. The uart cable is just a microUSB-USB cable if you use the UART adapter board (http://www.96boards.org/products/mezzanine/uarts).
Having both consoles together can make it hard to read, but if you want to separate them out, then you will need another uart cable (adapter board won’t work). You’ll also have some soldering to do since the connector pins are not there.