crypto: hisilicon/sec2 - Add pbuffer mode for SEC driver

In the scenario of SMMU translation, the SEC performance of short messages
(<512Bytes) cannot meet our expectations. To avoid this, we reserve the
plat buffer (PBUF) memory for small packets when creating TFM.

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>