net: phy: remove gen10g_suspend and gen10g_resume

phy_suspend() and phy_resume() are no-ops anyway if no callback is
defined. Therefore we don't need these stubs.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>