crypto: hisilicon/sec2 - Update IV and MAC operation

We have updated the operation method of IV and MAC address
to prepare for pbuf patch and fixed coding style.

Signed-off-by: Longfang Liu <liulongfang@huawei.com>
Signed-off-by: Zaibo Xu <xuzaibo@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>