target-*: Clean up cpu.h header guards

Most of them use guard symbols like CPU_$target_H, but we also have
__MIPS_CPU_H__ and __TRICORE_CPU_H__.  They all upset
scripts/clean-header-guards.pl.

The script dislikes CPU_$target_H because they don't match their file
name (they should, to make guard collisions less likely).  The others
are reserved identifiers.

Clean them all up: use guard symbol $target_CPU_H for
target-$target/cpu.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>

target-s390x/cpu.h

@@ -19,8 +19,9 @@
  * You should have received a copy of the GNU (Lesser) General Public
  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef CPU_S390X_H
-#define CPU_S390X_H
+
+#ifndef S390X_CPU_H
+#define S390X_CPU_H
 
 #include "qemu-common.h"
 #include "cpu-qom.h"