net: phy: move PHY package related code from phy.h to phy_package.c

Move PHY package related inline functions from phy.h to phy_package.c.
While doing so remove locked versions phy_package_read() and
phy_package_write() which have no user.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://patch.msgid.link/a4518379-7a5d-45f3-831c-b7fde6512c65@gmail.com


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