MdeModulePkg/Xhci: Fix TRT when data length is 0

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3418

According to xhci spec, at USB packet level, a Control Transfer
consists of multiple transactions partitioned into stages: a
setup stage, an optional data stage, and a terminating status
stage. If Data Stage does not exist, the Transfer Type flag(TRT)
should be No Data Stage.
So if data length equals to 0, TRT is set to 0.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Wenyi Xie <xiewenyi2@huawei.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>