dt-bindings: add jianda vendor prefix

This adds a vendor prefix "jianda" for Jiandangjing Technology Co., Ltd.

Signed-off-by: David Lechner <david@lechnology.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1514833336-22564-2-git-send-email-david@lechnology.com