cpu-common.h: Remove unnecessary guard on including targphys.h

There's no need to make the include of targphys.h conditional
on whether TARGET_PHYS_ADDR_BITS is defined, because targphys.h
itself checks that and does nothing if it isn't.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

cpu-common.h

@@ -3,9 +3,7 @@
 
 /* CPU interfaces that are target independent.  */
 
-#ifdef TARGET_PHYS_ADDR_BITS
 #include "targphys.h"
-#endif
 
 #ifndef NEED_CPU_H
 #include "poison.h"