arm: dts: socfpga: Add u-boot, dm-pre-reloc for sysmgr and clkmgr nodes

Add u-boot,dm-pre-reloc for sysmgr and clkmgr nodes to use it in SPL.
In preparation to get base address from DT.

Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
diff --git a/arch/arm/dts/socfpga_arria10.dtsi b/arch/arm/dts/socfpga_arria10.dtsi
index c11a5c0..cc529bc 100644
--- a/arch/arm/dts/socfpga_arria10.dtsi
+++ b/arch/arm/dts/socfpga_arria10.dtsi
@@ -96,7 +96,7 @@
 			fpga-mgr = <&fpga_mgr>;
 		};
 
-		clkmgr@ffd04000 {
+		clkmgr: clkmgr@ffd04000 {
 				compatible = "altr,clk-mgr";
 				reg = <0xffd04000 0x1000>;
 				u-boot,dm-pre-reloc;