arm64: zynqmp: Add gpio labels for modepin

Using labels helps with better identifications of chips.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/15b0f68077fb3c86d438caf8562de87367361c60.1652262769.git.michal.simek@amd.com
diff --git a/arch/arm/dts/zynqmp-sm-k26-revA.dts b/arch/arm/dts/zynqmp-sm-k26-revA.dts
index e904cd8..a2c88dc 100644
--- a/arch/arm/dts/zynqmp-sm-k26-revA.dts
+++ b/arch/arm/dts/zynqmp-sm-k26-revA.dts
@@ -89,6 +89,10 @@
 	};
 };
 
+&modepin_gpio {
+	label = "modepin";
+};
+
 &uart1 { /* MIO36/MIO37 */
 	status = "okay";
 };