[POWERPC] cell: Fix spu_info.h header export

It uses #ifdef __KERNEL__, so needs to be processed with unifdef.
Signed-off-by: NArnd Bergann <arnd.bergmann@de.ibm.com>
Acked-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

include/asm-powerpc/Kbuild

@@ -17,7 +17,6 @@ header-y += ipc.h
 header-y += poll.h
 header-y += shmparam.h
 header-y += sockios.h
-header-y += spu_info.h
 header-y += ucontext.h
 header-y += ioctl.h
 header-y += linkage.h
@@ -37,6 +36,7 @@ unifdef-y += posix_types.h
 unifdef-y += ptrace.h
 unifdef-y += seccomp.h
 unifdef-y += signal.h
+unifdef-y += spu_info.h
 unifdef-y += termios.h
 unifdef-y += types.h
 unifdef-y += unistd.h