Add a stub cpu_idle() function for sparc64, alpha, powerpc. This is a

MI declared function so it should be everywhere.

sys/alpha/alpha/machdep.c

@@ -1731,6 +1731,12 @@ cpu_halt(void)
 	prom_halt(1);
 }
 
+void
+cpu_idle(void)
+{
+	/* Insert code to halt (until next interrupt) for the idle loop */
+}
+
 /*
  * Clear registers on exec
  */

sys/powerpc/aim/machdep.c

@@ -609,6 +609,12 @@ cpu_halt(void)
 	OF_exit();
 }
 
+void
+cpu_idle(void)
+{
+	/* Insert code to halt (until next interrupt) for the idle loop */
+}
+
 /*
  * Set set up registers on exec.
  */

sys/powerpc/powerpc/machdep.c

@@ -609,6 +609,12 @@ cpu_halt(void)
 	OF_exit();
 }
 
+void
+cpu_idle(void)
+{
+	/* Insert code to halt (until next interrupt) for the idle loop */
+}
+
 /*
  * Set set up registers on exec.
  */

sys/sparc64/sparc64/machdep.c

@@ -670,6 +670,12 @@ sparc64_shutdown_final(void *dummy, int howto)
 		cpu_halt();
 }
 
+void
+cpu_idle(void)
+{
+	/* Insert code to halt (until next interrupt) for the idle loop */
+}
+
 int
 ptrace_set_pc(struct thread *td, u_long addr)
 {