ARM: dts: da850: use gpio-ranges

This makes use of the gpio-ranges feature that connects GPIO
controllers and PINMUX controllers.

In da850.dtsi, pinctrl-single,gpio-range is added to the pinmux node
and gpio-ranges is added to the GPIO node. Unfortunately, the way the
pinctrl-single driver enumerates the pins (starting with LSB) causes
them to be in reverse order compared to the way the gpios are assigned.
As a result, we have to declare the mapping for each GPIO individually.

This also lets us remove all of the GPIO pinmuxes from
da850-lego-ev3.dts. (Other da850 boards do not currently have any
GPIO pinmuxes declared.)

Acked-by: Linus Walleij <linus.wallei@linaro.org>
Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>