Revert "BaseTools/PatchCheck.py: Add LicenseCheck"

This reverts commit a4cfb842.
This commit suggests inclusion of non-edk2+license content without
a contribution agreement is something the community has made a
decision on, which is incorrect.

Cc: Shenglei Zhang <shenglei.zhang@intel.com>
Cc: Yuwei Chen <yuwei.chen@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Signed-off-by: Leif Lindholm <leif@nuviainc.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>