dts: scobc_a1: Add FPGA related definitions

Adds SC-OBC Module A1 FPGA System Register and System Monitor
definitions to DTS.

  - System Register
    Registers for system control of SC-OBC Module A1
    Link: https://sc-obc-fpga-technical-reference-manual.readthedocs.io/ja/latest/#org19067cd

  - System Monitor
    Module for monitoring the SC-OBC Module A1 system
    Link: https://sc-obc-fpga-technical-reference-manual.readthedocs.io/ja/latest/#org8832978

Signed-off-by: Takuya Sasaki <takuya.sasaki@spacecubics.com>

boards/sc/scobc_a1/dts/bindings/sc,sysmon.yaml

@@ -0,0 +1,12 @@
+# Copyright (c) 2025 Space Cubics Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+description: SC-OBC Module A1 System Monitor
+
+compatible: "sc,sysmon"
+
+include: base.yaml
+
+properties:
+  reg:
+    required: true

boards/sc/scobc_a1/dts/bindings/sc,sysreg.yaml

@@ -0,0 +1,12 @@
+# Copyright (c) 2025 Space Cubics Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+description: SC-OBC Module A1 System Register
+
+compatible: "sc,sysreg"
+
+include: base.yaml
+
+properties:
+  reg:
+    required: true

boards/sc/scobc_a1/scobc_a1.dts

@@ -46,6 +46,16 @@
 			interrupts = <0 0>;
 			reg = <0x4f010000 0x10000>;
 		};
+
+		sysreg: sysreg@4f000000 {
+			compatible = "sc,sysreg";
+			reg = <0x4f000000 0x10000>;
+		};
+
+		sysmon: sysmon@4f040000 {
+			compatible = "sc,sysmon";
+			reg = <0x4f040000 0x1000>;
+		};
 	};
 };