arm64: dts: mediatek: cherry: Enable Elantech eKTH3000 i2c trackpad

The Cherry platform uses an Elantech touchpad/trackpad: enable
probing it at address 0x15 on I2C1.

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/20220902081156.38526-7-angelogioacchino.delregno@collabora.com


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