crypto: omap-sham - Verify page zone of scatterlists before starting DMA

In certain platforms like DRA7xx having memory > 2GB with LPAE enabled
has a constraint that DMA can be done with the initial 2GB and marks it
as ZONE_DMA. But openssl when used with cryptodev does not make sure that
input buffer is DMA capable. So, adding a check to verify if the input
buffer is capable of DMA.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reported-by: Aparna Balasubramanian <aparnab@ti.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>