OvmfPkg: Add the MIT license to License.txt.

The MIT license will be used for several source files that are necessary
for the Xen PV drivers. So this patch makes it explicit by adding the
license with a note about which directory will have source files under
this license.

Change in V3:
  New patch

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Anthony PERARD <[email protected]>
Reviewed-by: Jordan Justen <[email protected]>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16256 6f19259b-4bc3-4df7-8a09-765794883524

OvmfPkg/License.txt

@@ -23,3 +23,28 @@ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
+
+
+Some files are subject to the following license, the MIT license. Those files
+are located in:
+- OvmfPkg/Include/IndustryStandard/Xen/
+- OvmfPkg/XenBusDxe/
+- OvmfPkg/XenPvBlkDxe/
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.