crypto: caam - 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.

the entropy delay interval should be doubled before performing the
retry.

also, ctrlpriv->rng4_sh_init and inst_handles both reads RNG DRNG
status register, but only inst_handles is updated before every retry.
so only check inst_handles and removing ctrlpriv->rng4_sh_init

Signed-off-by: Gaurav Jain <gaurav.jain@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>