Convert the at91_pinctrl driver to use the new fdt_pinctrl interface.
Create /tmp/bsdinstall_etc even if we aren't starting the installer so that
dhclient can write resolv.conf when used from the live environment.

PR:		176078
MFC after:	3 days
Replace the imx5 and imx6 iomux drivers with a single common driver that
uses the new fdt_pinctrl interface.