crypto: inside-secure - dynamic ring configuration allocation

The Inside Secure SafeXcel driver currently uses 4 rings, but the
eip197d engines has 8 of them. This patch updates the driver so that
rings are allocated dynamically based on the number of available rings
supported by a given engine.

Signed-off-by: Ofer Heifetz <oferh@marvell.com>
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>