[ARM] 4541/1: iop: defconfig updates

With the availability of the iop-adma driver iop platforms can now use
their offload engines for md-raid5 (copy+xor) and net-dma (tcp receive
copy) offload.

Cc: Lennert Buytenhek <kernel@wantstofly.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>