Enable the reporting of error counters through sysfs for QAT GEN6
devices and update the ABI documentation.

This enables the reporting of the following:
   - errors_correctable - hardware correctable errors that allow the
     system to recover without data loss.
   - errors_nonfatal: errors that can be isolated to specific in-flight
     requests.
   - errors_fatal: errors that cannot be contained to a request,
     requiring a Function Level Reset (FLR) upon occurrence.

Signed-off-by: Suman Kumar Chakraborty <suman.kumar.chakraborty@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Introduce ras counters interface for counting QAT specific device
errors and expose them through the newly created qat_ras sysfs
group attribute.

This adds the following attributes:

- errors_correctable: number of correctable errors
- errors_nonfatal: number of uncorrectable non fatal errors
- errors_fatal: number of uncorrectable fatal errors
- reset_error_counters: resets all counters

These counters are initialized during device bring up and cleared
during device shutdown and are applicable only to QAT GEN4 devices.

Signed-off-by: Shashank Gupta <shashank.gupta@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Tero Kristo <tero.kristo@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>