linux-wandboard

crypto: caam - Reintroduce DESC_MAX_USED_BYTES

I incorrectly removed DESC_MAX_USED_BYTES when enlarging the size
of the shared descriptor buffers, thus making it four times larger
than what is necessary.  This patch restores the division by four
calculation.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>