Fixes the following W=1 kernel build warning(s):

 drivers/thunderbolt/tb.c:535: warning: Function parameter or member 'sw' not described in 'tb_scan_switch'
 drivers/thunderbolt/tb.c:551: warning: Function parameter or member 'port' not described in 'tb_scan_port'
 drivers/thunderbolt/tb.c:711: warning: Function parameter or member 'tb' not described in 'tb_free_invalid_tunnels'
 drivers/thunderbolt/tb.c:726: warning: Function parameter or member 'sw' not described in 'tb_free_unplugged_children'
 drivers/thunderbolt/tb.c:1129: warning: Function parameter or member 'work' not described in 'tb_handle_hotplug'
 drivers/thunderbolt/tb.c:1239: warning: Function parameter or member 'tb' not described in 'tb_handle_event'
 drivers/thunderbolt/tb.c:1239: warning: Function parameter or member 'type' not described in 'tb_handle_event'
 drivers/thunderbolt/tb.c:1239: warning: Function parameter or member 'buf' not described in 'tb_handle_event'
 drivers/thunderbolt/tb.c:1239: warning: Function parameter or member 'size' not described in 'tb_handle_event'
 drivers/thunderbolt/tb.c:1239: warning: expecting prototype for tb_schedule_hotplug_handler(). Prototype was for tb_handle_event() instead

Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Michael Jamet <michael.jamet@intel.com>
Cc: Yehezkel Bernat <YehezkelShB@gmail.com>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>