ARM: at91: fix pinctrl driver selection

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: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>