dt-bindings: Add vendor prefix for Chefree

The Chefree Technology Corp. is an LCD panel manufacturer.

Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Rob Herring <robh@kernel.org>
Cc: dri-devel@lists.freedesktop.org
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200728201242.4336-1-marex@denx.de