Expose the `auto_reset` sysfs attribute to configure the driver to reset
the device when a fatal error is detected.

When auto reset is enabled, the driver resets the device when it detects
either an heartbeat failure or a fatal error through an interrupt.

This patch is based on earlier work done by Shashank Gupta.
Signed-off-by: Damian Muszynski <damian.muszynski@intel.com>
Reviewed-by: Ahsan Atta <ahsan.atta@intel.com>
Reviewed-by: Markas Rapoportas <markas.rapoportas@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Mun Chun Yep <mun.chun.yep@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>