nctgpio: change default pin names to those used by the datasheet(s)

That is, instead of the current GPIO00 - GPIO15 the names will be GPIO00

• GPIO07, GPIO10 - GPIO17. The first digit is a GPIO "bank" / group

number and the second one is a pin number within the bank. Alternative
view is that the pin names are changed from decimal numbering scheme to
octal one (as there are 8 pins per bank).

Discussed with: cem, gonzo
MFC after: 2 weeks