ARM: dts: ux500: Rename DSI controller nodes

Rename the DSI controller nodes from "dsi-controller@"
to "dsi@" so they match the naming convention in the
YAML schema for DSI controllers.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20201104133758.1373298-1-linus.walleij@linaro.org


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>