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>