arm64: dts: mediatek: cherry: Wire up the ChromeOS Embedded Controller

Wire up the ChromeOS Embedded Controller on SPI0 and its communication
channel via SCP RPMSG along with all of the offered functionality,
including Keyboard, Smart Battery Metrics (SBS), keyboard backlight,
I2C tunnel, regulators and Type-C connector management.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220902081156.38526-3-angelogioacchino.delregno@collabora.com


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