arm: socfpga: dts: Add bank-name property to each GPIO bank

Add "bank-name" property to each GPIO bank to give it unique name.
The approach here is exactly the same as with the "regulator-name"
property for regulators.

Signed-off-by: Marek Vasut <marex@denx.de>
diff --git a/arch/arm/dts/socfpga.dtsi b/arch/arm/dts/socfpga.dtsi
index ded3093..8588221 100644
--- a/arch/arm/dts/socfpga.dtsi
+++ b/arch/arm/dts/socfpga.dtsi
@@ -549,6 +549,7 @@
 
 			porta: gpio-controller@0 {
 				compatible = "snps,dw-apb-gpio-port";
+				bank-name = "porta";
 				gpio-controller;
 				#gpio-cells = <2>;
 				snps,nr-gpios = <29>;
@@ -569,6 +570,7 @@
 
 			portb: gpio-controller@0 {
 				compatible = "snps,dw-apb-gpio-port";
+				bank-name = "portb";
 				gpio-controller;
 				#gpio-cells = <2>;
 				snps,nr-gpios = <29>;
@@ -589,6 +591,7 @@
 
 			portc: gpio-controller@0 {
 				compatible = "snps,dw-apb-gpio-port";
+				bank-name = "portc";
 				gpio-controller;
 				#gpio-cells = <2>;
 				snps,nr-gpios = <27>;