rockchip: video: defconfig: Add mipi dsi support for evb-rk3288

Add support for rk3288 mipi dsi.

Signed-off-by: Eric Gao <eric.gao@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>