ARM: shmobile: emev2 dtsi: Add PFC information

With this information all GPIOs can make use of the PFC functionality.

Signed-off-by: Niklas Söderlund <niso@kth.se>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>