powerpc: restore some missing spu syscalls

A couple of system calls were inadventently removed from the table during
a bugfix for 32-bit powerpc entry. Restore the original behavior.

Fixes: e2375062 ("powerpc/32: fix syscall wrappers with 64-bit arguments of unaligned register-pairs")
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>