crypto: qat - num_rings_per_bank is device dependent

This change is to allow support for QAT devices that may not have 16
rings per bank.
The rings structure in bank is allocated dynamically based on the number
of banks supported by a device.

Note that in the error path in adf_init_bank(), ring->inflights is set
to NULL after the free to silence a false positive double free reported
by clang scan-build.

Signed-off-by: Ahsan Atta <ahsan.atta@intel.com>
Co-developed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Fiona Trahe <fiona.trahe@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>