drm/i915/uc: Make unexpected firmware versions an error in debug builds

If the DEBUG_GEM config option is set then escalate the 'unexpected
firmware version' message from a notice to an error. This will ensure
that the CI system treats such occurences as a failure and logs a bug
about it (or fails the pre-merge testing).

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230502234007.1762014-7-John.C.Harrison@Intel.com