drm/i915/huc: fix version parsing from CSS header

The HuC FW has silently switched to encoding the version the same way as
the GuC FW does, i.e. major.minor.patch instead of just major.minor. All
the current blobs follow the new scheme, but since minor and patch are
both zero there is no difference in the end results and we happily load
them. New binaries, however, will have non-zero values in there, so we
need to make sure to parse them correctly.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Acked-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190925222121.4000-1-daniele.ceraolospurio@intel.com