Platform/Intel/PurleyOpenBoardPkg: Replace BSD License with BSD+Patent License

https://bugzilla.tianocore.org/show_bug.cgi?id=1373

Replace BSD 2-Clause License with BSD+Patent License.  This change is
based on the following emails:

  https://lists.01.org/pipermail/edk2-devel/2019-February/036260.html
  https://lists.01.org/pipermail/edk2-devel/2018-October/030385.html

RFCs with detailed process for the license change:

  V3: https://lists.01.org/pipermail/edk2-devel/2019-March/038116.html
  V2: https://lists.01.org/pipermail/edk2-devel/2019-March/037669.html
  V1: https://lists.01.org/pipermail/edk2-devel/2019-March/037500.html



Cc: Shifei A Lu <shifei.a.lu@intel.com>
Cc: Xiaohu Zhou <bowen.zhou@intel.com>
Cc: Isaac W Oram <isaac.w.oram@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Isaac W <Oram&lt;Isaac.w.oram@intel.com>