dt-bindings: Add vendor prefix for LEGO

[ Upstream commit 7dcc31e2e68a386a29070384b51683ece80982bf ]

Add a vendor prefix for LEGO Systems A/S

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>