ARM: dts: am335x/am437x: remove unneeded unit name for fixed regulators

This patch fixes the following DTC warnings for many boards:

"Node /fixedregulator@0 has a unit name, but no reg property"

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am335x-sl50.dts

@@ -103,7 +103,7 @@
 		reset-gpios = <&gpio1 20 GPIO_ACTIVE_LOW>;
 	};
 
-	vmmcsd_fixed: fixedregulator@0 {
+	vmmcsd_fixed: fixedregulator0 {
 		compatible = "regulator-fixed";
 		regulator-name = "vmmcsd_fixed";
 		regulator-min-microvolt = <3300000>;