crypto/rng: double the entropy delay interval for retry

crypto/rng: double the entropy delay interval for retry

During entropy evaluation, if the generated samples fail any statistical test,
then, all of the bits will be discarded, and a second set of samples will be
generated and tested.

Double the ent_delay to give more chance to pass before performing retry.

Signed-off-by: Gaurav Jain <gaurav.jain@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>