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>
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 5c7a279..776efe6 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -16,8 +16,9 @@
  * 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_I386_H
-#define CPU_I386_H
+
+#ifndef I386_CPU_H
+#define I386_CPU_H
 
 #include "qemu-common.h"
 #include "cpu-qom.h"
@@ -1607,4 +1608,4 @@
 /* cpu.c */
 bool cpu_is_bsp(X86CPU *cpu);
 
-#endif /* CPU_I386_H */
+#endif /* I386_CPU_H */