devicetree: bindings: Add vendor prefix for Tronsmart

Tronsmart is a China based company building consumer electronic
devices.
Signed-off-by: NMatthias Brugger <mbrugger@suse.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NCarlo Caione <carlo@endlessm.com>

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -238,6 +238,7 @@ toshiba	Toshiba Corporation
 toumaz	Toumaz
 tplink	TP-LINK Technologies Co., Ltd.
 tronfy	Tronfy
+tronsmart	Tronsmart
 truly	Truly Semiconductors Limited
 upisemi	uPI Semiconductor Corp.
 usi	Universal Scientific Industrial Co., Ltd.