net: phy: microchip_t1: Don't set .config_aneg

The .config_aneg in microchip_t1 is genphy_config_aneg, so it's not
needed, because the phy core will call genphy_config_aneg() if the
.config_aneg is NULL.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20201109091605.3951c969@xhacker.debian
Signed-off-by: Jakub Kicinski <kuba@kernel.org>