crypto: caam/qi2 - fix DMA mapping of stack memory

Commits c19650d6 ("crypto: caam - fix DMA mapping of stack memory")
and 65055e21 ("crypto: caam - fix hash context DMA unmap size")
fixed the ahash implementation in caam/jr driver such that req->result
is not DMA-mapped (since it's not guaranteed to be DMA-able).

Apply a similar fix for ahash implementation in caam/qi2 driver.

Cc: <stable@vger.kernel.org> # v4.20+
Fixes: 3f16f6c9 ("crypto: caam/qi2 - add support for ahash algorithms")
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>