Move the selection of the pinctrl driver to SoC family level since we
have two pinctrl drivers. It is useless to select one which is not
compatible with the SoC.

[abelloni: fixed pm.c when only sama2d2 is selected]
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>