crypto: caam - adjust RNG timing to support more devices

Adjust RNG timing parameters to support more i.MX6 devices.

Signed-off-by: Victoria Milhoan <vicki.milhoan@freescale.com>
Signed-off-by: Dan Douglass <dan.douglass@nxp.com>
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Reviewed-by: Gaurav Jain <gaurav.jain@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>