BaseTools: Support recent versions of cx_freeze.

BaseTools: Support recent versions of cx_freeze.

This patch fixes the assumed invalid command to start recent versions
of cx_freeze on Windows, which are python and not Windows
executables. To launch them correctly, the '$(PYTHON_HOME)\python'
prefix has been added, so that Python can interpret the tool.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Marvin Haeuser <Marvin.Haeuser@outlook.com>
Reviewed-by: Yonghong Zhu <yonghong.zhu@intel.com>