net: stmmac: ingenic: use stmmac_get_phy_intf_sel()

net: stmmac: ingenic: use stmmac_get_phy_intf_sel()

Use stmmac_get_phy_intf_sel() to decode the PHY interface mode to the
phy_intf_sel value, validate the result against the SoC specific
supported phy_intf_sel values, and pass into the SoC specific
set_mode() methods, replacing the local phy_intf_sel variable. This
provides the value for the MACPHYC_PHY_INFT_MASK field.

Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1vHHq8-0000000DjrJ-2NRK@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>