thunderbolt: path: Fix kernel-doc descriptions of non-static functions

Fix kernel-doc descriptions of the two non-static functions. This also
gets rid of the warnings on W=1 build.

Reported-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Lee Jones <lee.jones@linaro.org>

drivers/thunderbolt/path.c

@@ -466,6 +466,7 @@ void tb_path_deactivate(struct tb_path *path)
 
 /**
  * tb_path_activate() - activate a path
+ * @path: Path to activate
  *
  * Activate a path starting with the last hop and iterating backwards. The
  * caller must fill path->hops before calling tb_path_activate().
@@ -561,6 +562,7 @@ int tb_path_activate(struct tb_path *path)
 
 /**
  * tb_path_is_invalid() - check whether any ports on the path are invalid
+ * @path: Path to check
  *
  * Return: Returns true if the path is invalid, false otherwise.
  */