arm64: dts: agilex: Add SysMgr to Ethernet nodes

Ethernet needs the System Manager to setup the low-level
interface and PHY.
Signed-off-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>

arch/arm64/boot/dts/intel/socfpga_agilex.dtsi

@@ -113,6 +113,7 @@ gmac0: ethernet@ff800000 {
 			rx-fifo-depth = <16384>;
 			snps,multicast-filter-bins = <256>;
 			iommus = <&smmu 1>;
+			altr,sysmgr-syscon = <&sysmgr 0x44 0>;
 			status = "disabled";
 		};
 
@@ -128,6 +129,7 @@ gmac1: ethernet@ff802000 {
 			rx-fifo-depth = <16384>;
 			snps,multicast-filter-bins = <256>;
 			iommus = <&smmu 2>;
+			altr,sysmgr-syscon = <&sysmgr 0x48 8>;
 			status = "disabled";
 		};
 
@@ -143,6 +145,7 @@ gmac2: ethernet@ff804000 {
 			rx-fifo-depth = <16384>;
 			snps,multicast-filter-bins = <256>;
 			iommus = <&smmu 3>;
+			altr,sysmgr-syscon = <&sysmgr 0x4c 16>;
 			status = "disabled";
 		};