ANDROID: fix up abi breakage in struct dwc3

Commit cf52c320 ("USB: dwc3: fix memory leak with using
debugfs_lookup()") added a new field to struct dwc3.  Fix this up by
using one of the reserved fields in the structure to handle the abi
break and update the .xml file to preserve things.

type 'struct dwc3' changed
  member 'union { struct dentry * debug_root; struct { u64 android_kabi_reserved2; }; union { }; }' was added
  member 'u64 android_kabi_reserved2' was removed

Fixes: cf52c320 ("USB: dwc3: fix memory leak with using debugfs_lookup()")
Bug: 161946584
Change-Id: I7bf60deb89e4d5c4a9bc4cbcf68912cef21358ce
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>