dts: gpio: Add Microchip XEC GPIO macros for use in device tree

Microchip XEC devices specify GPIO pin using octal numbering and
organize pins in banks of 32. Chip documentation does not use
bank naming rather naming each pin by its octal number. This has
led to the developer having to calculate the bit position of a pin
in its 32-bit bank when a specifying the pin for GPIO usage. We
created a set of defines for all possible GPIO pins that specify
the DT GPIO bank name used in the chip level DTSI files and the
bit position in that bank.

Signed-off-by: Jay Vasanth <jay.vasanth@microchip.com>