arm64: dts: mediatek: mt8516: remove 2 invalid i2c clocks

The two clocks "main-source" and "main-sel" are not present in the
driver and not defined in the binding documentation. Remove them
as they are not used and not described in the documentation.

Signed-off-by: Fabien Parent <fparent@baylibre.com>
Link: https://lore.kernel.org/r/20211110193520.488-1-fparent@baylibre.com


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