target-m68k: Rename helpers.h to helper.h

This brings the m68k target in line with all other targets.

Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>

target-m68k/helper.c

@@ -21,7 +21,7 @@
 #include "cpu.h"
 #include "exec/gdbstub.h"
 
-#include "helpers.h"
+#include "helper.h"
 
 #define SIGNBIT (1u << 31)
 

target-m68k/op_helper.c

@@ -17,7 +17,7 @@
  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  */
 #include "cpu.h"
-#include "helpers.h"
+#include "helper.h"
 
 #if defined(CONFIG_USER_ONLY)
 

target-m68k/translate.c

@@ -23,9 +23,9 @@
 #include "tcg-op.h"
 #include "qemu/log.h"
 
-#include "helpers.h"
+#include "helper.h"
 #define GEN_HELPER 1
-#include "helpers.h"
+#include "helper.h"
 
 //#define DEBUG_DISPATCH 1
 
@@ -110,7 +110,7 @@ void m68k_tcg_init(void)
     store_dummy = tcg_global_mem_new(TCG_AREG0, -8, "NULL");
 
 #define GEN_HELPER 2
-#include "helpers.h"
+#include "helper.h"
 }
 
 static inline void qemu_assert(int cond, const char *msg)