net: phy: remove fixup-related definitions from phy.h which are not used outside phylib

Certain fixup-related definitions aren't used outside phy_device.c.
So make them private and remove them from phy.h.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/ea6fde13-9183-4c7c-8434-6c0eb64fc72c@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>