net: dsa: mv88e6xxx: Wait for EEPROM done after HW reset

net: dsa: mv88e6xxx: Wait for EEPROM done after HW reset

[ Upstream commit a3dcb3e7e70c72a68a79b30fc3a3adad5612731c ]

When the switch is hardware reset, it reads the contents of the
EEPROM. This can contain instructions for programming values into
registers and to perform waits between such programming. Reading the
EEPROM can take longer than the 100ms mv88e6xxx_hardware_reset() waits
after deasserting the reset GPIO. So poll the EEPROM done bit to
ensure it is complete.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Ruslan Sushko <rus@sushko.dev>
Link: https://lore.kernel.org/r/20201116164301.977661-1-rus@sushko.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>