crypto/fsl: Fix RNG instantiation failure.

Corrected the order of arguments in memset in run_descriptor
function. Wrong order of argumnets led to improper initialization
of members of struct type result. This resulted in RNG instantiation
error.

Signed-off-by: Gaurav Rana <gaurav.rana@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>