powerpc: Fix build breakage in jump_label.c

Should do what other architectures do and wrap all that code into
the appropriate ifdef
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/jump_label.c

@@ -11,6 +11,7 @@
 #include <linux/jump_label.h>
 #include <asm/code-patching.h>
 
+#ifdef HAVE_JUMP_LABEL
 void arch_jump_label_transform(struct jump_entry *entry,
 			       enum jump_label_type type)
 {
@@ -21,3 +22,4 @@ void arch_jump_label_transform(struct jump_entry *entry,
 	else
 		patch_instruction(addr, PPC_INST_NOP);
 }
+#endif