tile: remove cpu_idle_on_new_stack

This routine isn't used unless CONFIG_HOMECACHE is enabled, which
isn't even available as a public configuration option yet.
Since it no longer links correctly in 3.4, just remove it for now.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

arch/tile/include/asm/thread_info.h

@@ -91,11 +91,6 @@ extern void smp_nap(void);
 /* Enable interrupts racelessly and nap forever: helper for cpu_idle(). */
 extern void _cpu_idle(void);
 
-/* Switch boot idle thread to a freshly-allocated stack and free old stack. */
-extern void cpu_idle_on_new_stack(struct thread_info *old_ti,
-				  unsigned long new_sp,
-				  unsigned long new_ss10);
-
 #else /* __ASSEMBLY__ */
 
 /*

arch/tile/kernel/entry.S

@@ -68,20 +68,6 @@ STD_ENTRY(KBacktraceIterator_init_current)
 	jrp lr   /* keep backtracer happy */
 	STD_ENDPROC(KBacktraceIterator_init_current)
 
-/*
- * Reset our stack to r1/r2 (sp and ksp0+cpu respectively), then
- * free the old stack (passed in r0) and re-invoke cpu_idle().
- * We update sp and ksp0 simultaneously to avoid backtracer warnings.
- */
-STD_ENTRY(cpu_idle_on_new_stack)
-	{
-	 move sp, r1
-	 mtspr SPR_SYSTEM_SAVE_K_0, r2
-	}
-	jal free_thread_info
-	j cpu_idle
-	STD_ENDPROC(cpu_idle_on_new_stack)
-
 /* Loop forever on a nap during SMP boot. */
 STD_ENTRY(smp_nap)
 	nap