net: mdio-mux-meson-g12a: force internal PHY off on mux switch

net: mdio-mux-meson-g12a: force internal PHY off on mux switch

Force the internal PHY off then on when switching to the internal path.
This fixes problems where the PHY ID is not properly set.

Fixes: 7090425104db ("net: phy: add amlogic g12a mdio mux support")
Suggested-by: Qi Duan <qi.duan@amlogic.com>
Co-developed-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20230124101157.232234-1-jbrunet@baylibre.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>