Revert "usb: dwc3: Decouple USB 2.0 L1 & L2 events"

This reverts commit 6b3af2ad which is
commit 843714bb upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: Ib96ea8055f2104af87ae69497c0a4ee84b7df024
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>