Gpio in vexpress

[ido berenbaum]

Hi, I was trying to understand the architecture of the vexpress virtual
machine in regards to adding new gpios that are going to be external.
First, is it right to act as if I am developing on a physical board and add
the gpios to the VexpressMachineState struct?
Secondly, which gpio type fits here? I see that for fsl_imx7 it is the
imx_gpio, but what is for vexpress? Should I create one?
Or, can I use pl061?