ARM: dts: bcm21664: Replace spaces with a tab

Fix checkpatch warning:

WARNING: please, no spaces at the start of a line
Signed-off-by: Stanislav Jakubek <stano.jakubek@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

arch/arm/boot/dts/bcm21664.dtsi

@@ -27,7 +27,7 @@ chosen {
 		bootargs = "console=ttyS0,115200n8";
 	};
 
-       cpus {
+	cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;