crypto: caam - FIX RNG init for RNG greater than equal to 4

For SEC including a RNG block version >= 4, special initialization
must occur before any descriptor that uses RNG block can be
submitted. This initialization is required not only for SEC
with version greater than 5.0, but for SEC with RNG version >=4.
There may be a case where RNG has already been instantiated by
u-boot or boot ROM code.In such SoCs, if RNG is initialized again
SEC would returns "Instantiation error". Hence, the initialization
status of RNG4 should be also checked before doing RNG init.

Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com>
Signed-off-by: Alex Porosanu <alexandru.porosanu@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
Reviewed-by: Vakul Garg <vakul@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>