UPSTREAM: spi/rockchip: add rk3036/rk3228/rk3368 SoCs for spi document

UPSTREAM: spi/rockchip: add rk3036/rk3228/rk3368 SoCs for spi document

We had supported the rk3036/rk3066/rk3188/rk3228/rk3288/rk3368/rk3399
family SoCs in linux kernel.

Let's add the other SoCs, in order to a better understanding from the
rockchip spi document.

Change-Id: If527c4356c2049a2d5bfc88ffec4cd1350f7b9be
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
(cherry picked from git.kernel.org next/linux-next.git master
 commit 1eb1c5dc601a9f53d5bd53702d95afad337d35d2)