dt-bindings: add vendor prefix for Touchless Biometric Systems AG

TBS is a company providing biometrics products and solution in Access
control and time management.

Signed-off-by: Tomas Novotny <tomas@novotny.cz>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>