crypto: ccree - use fine grained DMA mapping dir

Use a fine grained specification of DMA mapping directions
in certain cases, allowing both a more optimized operation
as well as shushing out a harmless, though persky
dma-debug warning.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Reported-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>