drm/i915/uc: Don't always fail on unavailable GuC firmware

If we failed to fetch default GuC firmware and we didn't plan
to use it for the submission and we never have used GuC before
then we may continue normal driver load, no need to declare
GPU wedged (we can use execlist for submission) and it is safe
to run without the HuC (users will check HuC status anyway).

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190818095204.31568-3-michal.wajdeczko@intel.com