dt-bindings: arm: mediatek: Sort entries by SoC then board compatibles

Some of the new MediaTek board entries were inserted in a chronological
order, or just randomly. This makes it harder to search for an entry.

Sort the entries by first grouping by SoC, then sorting by board
compatible strings. Also add a comment at the top asking people to do
the same.

Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240126083802.2728610-2-wenst@chromium.org


Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>