arm64: dts: mediatek: cherry: Add keyboard mapping for the top row

Chromebooks' embedded keyboards differ from standard layouts for the
top row, as this one doesn't have the standard function keys but
shortcuts instead: map these keys to achieve the functionality that
is pictured on the printouts.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/r/20220902081156.38526-5-angelogioacchino.delregno@collabora.com


Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>