dt-bindings: vendor-prefixes: add jethome prefix

JetHome is trademark of IP Sokolov P.A., manufacturer of home automation
devices.

Signed-off-by: Vyacheslav Bocharov <adeep@lexina.in>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20210915085715.1134940-3-adeep@lexina.in