ANDROID: GKI: USB: XHCI: add Android ABI padding to lots of xhci structures

Given that the xhci driver seems to be one of the more "modified" by
vendors, and that the xhci core is going to be built into the kernel in
the GKI 2 Android kernel, the xhci "platform" api is now a stable
boundry.

Try to handle any future changes in this api by adding some kabi padding
fields to allow for room to grow and change over the next 5+ years as
needed.

Bug: 151154716
Bug: 182336717
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I55c8cad8c8c51330fc2d72df41a1f04229a22e98