tools/python: remove broken xl binding

tools/python: remove broken xl binding

Various people say this binding doesn't compile or doesn't work. Remove
it for the benefit of xl feature development -- so that new features
won't need to worry about making this broken binding happy.

This isn't going to expose any user visible changes because that module
is not built by default.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Zhigang Wang <zhigang.x.wang@oracle.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>