ARM: mvebu: fix GPIO config on the Linksys boards

Some of the GPIO configs were wrong in the submitted DTS files,
this patch fixes all affected boards.

Signed-off-by: Imre Kaloz <kaloz@openwrt.org>

Cc: <stable@vger.kernel.org> # v4.1 +
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>