ARM: dts: OMAP2+: 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>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Benoit Cousson <benoit.cousson@linaro.org>
diff --git a/arch/arm/boot/dts/omap2.dtsi b/arch/arm/boot/dts/omap2.dtsi
index e6e4587..f39b237 100644
--- a/arch/arm/boot/dts/omap2.dtsi
+++ b/arch/arm/boot/dts/omap2.dtsi
@@ -8,6 +8,8 @@
  * kind, whether express or implied.
  */
 
+#include <dt-bindings/gpio/gpio.h>
+
 #include "skeleton.dtsi"
 
 / {