hw/arm/aspeed: Introduce AspeedCoprocessor class and base implementation

Add a new AspeedCoprocessor class that defines the foundational structure for
ASPEED coprocessor models. This class encapsulates a base DeviceState with
links to system memory, clock, and peripheral components such as SCU, SCUIO,
Timer Controller, and UARTs.

Introduce the corresponding implementation file
aspeed_coprocessor_common.c, which provides the aspeed_coprocessor_realize()
method, property registration, and QOM type registration. The class is marked
as abstract and intended to serve as a common base for specific coprocessor
variants (e.g. SSP/TSP subsystems).

This establishes a reusable and extensible framework for modeling ASPEED
coprocessor devices.

Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20251013054334.955331-10-jamin_lin@aspeedtech.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

include/hw/arm/aspeed_coprocessor.h

@@ -0,0 +1,44 @@
+/*
+ * ASPEED Coprocessor
+ *
+ * Copyright (C) 2025 ASPEED Technology Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef ASPEED_COPROCESSOR_H
+#define ASPEED_COPROCESSOR_H
+
+#include "qom/object.h"
+#include "hw/arm/aspeed_soc.h"
+
+struct AspeedCoprocessorState {
+    DeviceState parent;
+
+    MemoryRegion *memory;
+    MemoryRegion sram;
+    Clock *sysclk;
+
+    AspeedSCUState scu;
+    AspeedSCUState scuio;
+    AspeedTimerCtrlState timerctrl;
+    SerialMM uart[ASPEED_UARTS_NUM];
+};
+
+#define TYPE_ASPEED_COPROCESSOR "aspeed-coprocessor"
+OBJECT_DECLARE_TYPE(AspeedCoprocessorState, AspeedCoprocessorClass,
+                    ASPEED_COPROCESSOR)
+
+struct AspeedCoprocessorClass {
+    DeviceClass parent_class;
+
+    /** valid_cpu_types: NULL terminated array of a single CPU type. */
+    const char * const *valid_cpu_types;
+    uint32_t silicon_rev;
+    const hwaddr *memmap;
+    const int *irqmap;
+    int uarts_base;
+    int uarts_num;
+};
+
+#endif /* ASPEED_COPROCESSOR_H */