ARM: dts: at91: vinco: fix regulator name

vcc_3v3_reg is a fixed regulator and doesn't need a reg property. Remove
its unit-address.

Solves:
Warning (unit_address_vs_reg): Node /fixedregulator@0 has a unit name, but no reg property
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

arch/arm/boot/dts/at91-vinco.dts

@@ -245,7 +245,7 @@
 
 	};
 
-	vcc_3v3_reg: fixedregulator@0 {
+	vcc_3v3_reg: fixedregulator_3v3 {
 		compatible = "regulator-fixed";
 		regulator-name = "VCC 3V3";
 		regulator-min-microvolt = <3300000>;