crypto: inside-secure - Add support for HW with less ring AIC's than rings

The current driver assumes one dedicated ring interrupt controller per
ring. However, some existing EIP(1)97 HW has less ring AIC's than rings.
This patch allows the driver to work with such HW by detecting how many
ring AIC's are present and restricting the number of rings it *uses* by
the number of ring AIC's present. This allows it to at least function.
(optimization for the future: add ring dispatch functionality in the
interrupt service routine such that multiple rings can be supported from
one ring AIC, allowing all rings to be used)

Signed-off-by: Pascal van Leeuwen <pvanleeuwen@verimatrix.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>