hw/riscv/sifive_u: Create a SiFive U SoC object

Create a SiFive Unleashed U54 SoC and use that in the sifive_u machine.

We leave the SoC, RAM, device tree and reset/fdt loading as part of the
machine. All the other device creation has been moved to the SoC.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Michael Clark <mjc@sifive.com>

include/hw/riscv/sifive_u.h

@@ -19,13 +19,25 @@
 #ifndef HW_SIFIVE_U_H
 #define HW_SIFIVE_U_H
 
+#define TYPE_RISCV_U_SOC "riscv.sifive.u.soc"
+#define RISCV_U_SOC(obj) \
+    OBJECT_CHECK(SiFiveUSoCState, (obj), TYPE_RISCV_U_SOC)
+
+typedef struct SiFiveUSoCState {
+    /*< private >*/
+    SysBusDevice parent_obj;
+
+    /*< public >*/
+    RISCVHartArrayState cpus;
+    DeviceState *plic;
+} SiFiveUSoCState;
+
 typedef struct SiFiveUState {
     /*< private >*/
     SysBusDevice parent_obj;
 
     /*< public >*/
-    RISCVHartArrayState soc;
-    DeviceState *plic;
+    SiFiveUSoCState soc;
     void *fdt;
     int fdt_size;
 } SiFiveUState;