ARM: ux500: switch MSP to using pinctrl for pins

The MSP platform data callbacks use the old custom callbacks to
set the state of the pins, switch over to using pinctrl.

Cc: Ola Lilja <ola.o.lilja@stericsson.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>