pinctrl: nomadik: Silence compiler warn for !CONFIG_PM

The static suspend/resume functions were not being used while
!CONFIG_PM. Fix it and convert to CONFIG_PM_SLEEP.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>