net: dsa: sja1105: simplify static configuration reload

The static configuration reload saves the port speed in the static
configuration tables by first converting it from the internal
respresentation to the SPEED_xxx ethtool representation, and then
converts it back to restore the setting. This is because
sja1105_adjust_port_config() takes the speed as SPEED_xxx.

However, this is unnecessarily complex. If we split
sja1105_adjust_port_config() up, we can simply save and restore the
mac[port].speed member in the static configuration tables.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1svfMa-005ZIX-If@rmk-PC.armlinux.org.uk


Signed-off-by: Jakub Kicinski <kuba@kernel.org>