By default CT code was passing just payload of the G2H event
message, while Relay code expects full G2H message including
HXG header which contains DATA0 field. Fix that.

Fixes: 26d4481a ("drm/xe/guc: Start handling GuC Relay event messages")
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240419150351.358-1-michal.wajdeczko@intel.com