hw/core: Move cpu.c, cpu.h from qom/ to hw/core/

Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190709152053.16670-2-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Rebased onto merge commit 95a9457fd44; missed instances of qom/cpu.h
in comments replaced]
diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index 1c907d2..5742c3d 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -44,7 +44,7 @@
 #include "hw/xen/xen.h"
 #include "migration/qemu-file-types.h"
 #include "migration/vmstate.h"
-#include "qom/cpu.h"
+#include "hw/core/cpu.h"
 #include "trace.h"
 
 #define GPE_BASE 0xafe0