gdbstub: Remove unused include

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

gdbstub.c

@@ -20,7 +20,6 @@
 #include "qapi/error.h"
 #include "qemu/error-report.h"
 #include "qemu/cutils.h"
-#include "cpu.h"
 #include "trace-root.h"
 #ifdef CONFIG_USER_ONLY
 #include "qemu.h"