drm/i915/uc: Sanitize uC when GT is sanitized

The microcontrollers are part of GT so it makes logical sense to have
them sanitized at the same time. This also fixed an issue with our
status tracking where the FW load status is not reset around
hibernation.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@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/20190723091404.6449-2-chris@chris-wilson.co.uk