plat-nomadik: new sleep mode pincfg macros

This adds a few sleep mode pin config macros for sleep mode
for the Nomadik GPIO/pin controller.

Signed-off-by: Rickard Andersson <rickard.andersson@stericsson.com>
Signed-off-by: Rikard Olsson <rikard.p.olsson@stericsson.com>
Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>