dt-bindings: add vendor prefix for Vivax

Add vendor prefix for the Vivax brand by M SAN Grupa d.o.o.

Source (in Croatian): https://www.vivax.com/hr/o-nama.aspx



Signed-off-by: Nikola Pavlica <pavlica.nikola@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211002202905.509437-1-pavlica.nikola@gmail.com