Device trees allow mixing different kinds of GPIOs in one property. For
that it is usefull to only provide a pointer to an arbitrary location in
the property and initialize a GPIO from that.
The imx-gpio driver used in i.MX and i.MXRT BSPs generates a name based
on a fixed string. The original code only used one digit for the
controller. With the 13 GPIO controllers of the i.MXRT1166, that isn't
enough any more. This patch extends the name to two digits which should
be enough for the next controller generations.
