arm64: dts: mt8183: Add more fennel SKUs

Add fennel sku7 and fennel14 sku2, which use different audio codec than
previous fennel/fennel14 boards.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Link: https://lore.kernel.org/r/20211110063118.3412564-3-hsinyi@chromium.org
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>