net: stmmac: qcom-ethqos: set serdes speed using serdes_speed
ethqos->serdes_speed represents the current speed the serdes was
configured for, which should be the same as ethqos->speed. Since we
wish to remove ethqos->speed to simplify the code, switch to using the
serdes_speed instead.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/E1u3bYL-000EcE-5c@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>