ARM: dts: rockchip: relicense rk3288-evb* under GPLv2/X11

GPLv2-only devicetrees make reuse difficult for software components licensed
under a different license.

The consensus is that a GPL/X11 dual-license should allow all necessary uses,
so relicense the rk3288-evb files to this combination.

CCs were aquired by git shortlog -sne so it should've hopefully catched
every contributor.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Doug Anderson <dianders@chromium.org>
Acked-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Caesar Wang <caesar.wang@rock-chips.com>
Acked-by: Romain Perier <romain.perier@gmail.com>
Acked-by: Chris <Zhong&lt;zyw@rock-chips.com>
Acked-by: Roger Chen <roger.chen@rock-chips.com>
Acked-by: Yunzhi Li <lyz@rock-chips.com>

on behalf of Rockchip
Acked-by: Eddie Cai <eddie.cai@rock-chips.com>