drm/i915/huc: Reorganize HuC authentication

drm/i915/huc: Reorganize HuC authentication

Prepared intel_auth_huc to separate HuC specific functionality
from GuC send action. Created new header intel_huc.h to group
HuC specific declarations.

v2: Changed argument preparation for AUTHENTICATE_HUC.
s/intel_auth_huc/intel_huc_auth. Deferred creation of intel_huc.h
to later patch.

v3: Rebase as intel_guc.h is removed. Added param description to
intel_huc_auth. (Michal)

v4: Rebase as intel_guc.h is added again. :)

v5: Rebase w.r.t removal of GuC code restructuring.

v6-v7: Rebase.

v8: Tagged subject as drm/i915/huc. (Michal Wajdeczko)
Added kernel-doc description to intel_huc_auth and intel_guc_auth_huc.
s/dev_priv/i915 and removed unnecessary variable offset. (Joonas)

v9: Rebase. Had conflict with i915_modparams change.

Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1506410236-17926-1-git-send-email-sagar.a.kamble@intel.com