ARM: dts: AM33XX: Use existing constants for GPIOs

Use standard GPIO constants to enhance the readability of DT GPIOs.

Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Tested-by: Afzal Mohammed <afzal@ti.com>
Signed-off-by: Benoit Cousson <benoit.cousson@linaro.org>

diff --cc arch/arm/boot/dts/am335x-bone.dts
Simple merge

diff --cc arch/arm/boot/dts/am335x-evm.dts
Simple merge

diff --cc arch/arm/boot/dts/am335x-evmsk.dts
Simple merge

diff --cc arch/arm/boot/dts/am33xx.dtsi
Simple merge