Revert "dt-bindings: Add vendor prefix for LEGO"

This reverts commit 04e13a5e.

As Ben pointed out, these drivers don't exist in <=4.9.

Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>