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

[ Upstream commit 7083df59 ]

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: 70904251

 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>