pinctrl: berlin: fix BG2CD field widths

The previous register layout was incorrect, many of the fields having
fewer bits than were needed to represent all their modes. The new layout
is taken from the bootloader source of a BG2CD device.

Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>