i2c-nomadik: use pm_runtime API

Use the pm_runtime API for pins control.

Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Reviewed-by: Jonas Aberg <jonas.aberg@stericsson.com>
[deleted some surplus runtime PM code]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>