net: stmmac: move PHY handling out of __stmmac_open()/release()

net: stmmac: move PHY handling out of __stmmac_open()/release()

Move the PHY attachment/detachment from the network driver out of
__stmmac_open() and __stmmac_release() into stmmac_open() and
stmmac_release() where these actions will only happen when the
interface is administratively brought up or down. It does not make
sense to detach and re-attach the PHY during a change of MTU.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/E1v11A3-0000000774G-3PKY@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>