Used to obtain "dev_priv" from huc struct pointer.
We already have similar thing for guc.

Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>