crypto/fsl: fsl_hash: Fix crash in flush dcache

wrong end address passed to flush_dcache_range.
modified the flush_dache logic for scatter list elements.

Fixes: 1919f58a (crypto/fsl: fsl_hash: Fix dcache issue in caam_hash_finish)
Signed-off-by: Gaurav Jain <gaurav.jain@nxp.com>