arm64: dts: mt8183: kukui: Split out keyboard node and describe detachables

[ Upstream commit 82492c4e ]

Kukui devices krane, kodana, and kakadu use detachable keyboards, which
only have switches to be registered.

Change the keyboard node's compatible of those boards to the newly
introduced "google,cros-ec-keyb-switches", which won't include matrix
properties.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Link: https://lore.kernel.org/r/20220527045353.2483042-1-hsinyi@chromium.org


Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Stable-dep-of: 04bd6411 ("arm64: dts: mt8183: Move CrosEC base detection node to kukui-based DTs")
Signed-off-by: Sasha Levin <sashal@kernel.org>