This small series add the initial support for the Airoha AN8855 Switch. It's a 5 port Gigabit Switch with SGMII/HSGMII upstream port. This is starting to get in the wild and there are already some router having this switch chip. It's conceptually similar to mediatek switch but register and bits are different. And there is that massive Hell that is the PCS configuration. Saddly for that part we have absolutely NO documentation currently. There is this special thing where PHY needs to be calibrated with values from the switch efuse. (the thing have a whole cpu timer and MCU)
