ANDROID: GKI: phy: add Android ABI padding to some structures

Try to mitigate potential future driver core api changes by adding a
padding to stuct phy_device and struct phy_driver

Inspired by the upstream changes in 5.4.26 and 4.19.111

Bug: 151154716
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I8dbc5f76e9eddfc5741f944168222aedacd0a8bb