rtl838x: move dts-v1 to DTSI

The syntax of the shared SoC DTSI file determines the DTS version,
so no need to repeat the "/dts-v1/;" identifier in every file.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/rtl838x/dts/rtl8382_allnet_all-sg8208m.dts

@@ -1,5 +1,4 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
-/dts-v1/;
 
 #include "rtl838x.dtsi"
 

target/linux/rtl838x/dts/rtl8382_d-link_dgs-1210-16.dts

@@ -1,5 +1,3 @@
-/dts-v1/;
-
 #include "rtl838x.dtsi"
 
 #include <dt-bindings/input/input.h>

target/linux/rtl838x/dts/rtl838x.dtsi

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later OR MIT
 
+/dts-v1/;
+
 / {
 	#address-cells = <1>;
 	#size-cells = <1>;