hw/acpi/cpu: Use CPUState typedef

QEMU coding style recommend using structure typedefs:
https://www.qemu.org/docs/master/devel/style.html#typedefs

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Message-Id: <20240126220407.95022-2-philmd@linaro.org>

include/hw/acpi/cpu.h

@@ -20,7 +20,7 @@
 #include "hw/hotplug.h"
 
 typedef struct AcpiCpuStatus {
-    struct CPUState *cpu;
+    CPUState *cpu;
     uint64_t arch_id;
     bool is_inserting;
     bool is_removing;