ARM: mvebu: use GPIO DT defines in Armada 370/XP boards

Instead of harcoding 0 and 1 for the gpio specifications in the Armada
370/XP boards, use the <dt-bindings/gpio/gpio.h> header file and its
GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW definitions.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>