powerpc/smp: Use code patching to restore reset vector

Instead of hardcoding reset vector restore, use patch_instruction()
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/86xx/mpc86xx_smp.c

@@ -86,8 +86,7 @@ smp_86xx_kick_cpu(int nr)
 		mdelay(1);
 
 	/* Restore the exception vector */
-	*vector = save_vector;
-	flush_icache_range((unsigned long) vector, (unsigned long) vector + 4);
+	patch_instruction(vector, save_vector);
 
 	local_irq_restore(flags);
 

arch/powerpc/platforms/powermac/smp.c

@@ -832,8 +832,7 @@ static int smp_core99_kick_cpu(int nr)
 	mdelay(1);
 
 	/* Restore our exception vector */
-	*vector = save_vector;
-	flush_icache_range((unsigned long) vector, (unsigned long) vector + 4);
+	patch_instruction(vector, save_vector);
 
 	local_irq_restore(flags);
 	if (ppc_md.progress) ppc_md.progress("smp_core99_kick_cpu done", 0x347);