net: phy: add getters for public members in struct phy_package_shared

Add getters for public members, this prepares for making struct
phy_package_shared private to phylib. Declare the getters in a new header
file phylib.h, which will be used by PHY drivers only.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://patch.msgid.link/c6da0b27-4479-4717-9e16-643821b76bd8@gmail.com


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