drm/i915: Add some boring kerneldoc

Tooling appears very strict so lets pacify it by adding some comments,
even if fields are completely self-explanatory.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: b1123648 ("drm/i915: Add GuC submission interface version query")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Jose Souza <jose.souza@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240219132517.1868604-1-tvrtko.ursulin@linux.intel.com

include/uapi/drm/i915_drm.h

@@ -3572,9 +3572,13 @@ struct drm_i915_query_memory_regions {
  * struct drm_i915_query_guc_submission_version - query GuC submission interface version
  */
 struct drm_i915_query_guc_submission_version {
+	/** @branch: Firmware branch version. */
 	__u32 branch;
+	/** @major: Firmware major version. */
 	__u32 major;
+	/** @minor: Firmware minor version. */
 	__u32 minor;
+	/** @patch: Firmware patch version. */
 	__u32 patch;
 };