[x265] More CMake warnings of old-style policies

[Mario Rohkrämer]

With CMake 3.11, there are now already two deprecated old-style policies  
being warned:

+----
-- cmake version 3.11.1
CMake Deprecation Warning at CMakeLists.txt:10 (cmake_policy):
   The OLD behavior for policy CMP0025 will be removed from a future version
   of CMake.

   The cmake-policies(7) manual explains that the OLD behaviors of all
   policies are deprecated and that a policy should be set to OLD only under
   specific short-term circumstances.  Projects should be ported to the NEW
   behavior and not rely on setting a policy to OLD.


CMake Deprecation Warning at CMakeLists.txt:16 (cmake_policy):
   The OLD behavior for policy CMP0054 will be removed from a future version
   of CMake.

   The cmake-policies(7) manual explains that the OLD behaviors of all
   policies are deprecated and that a policy should be set to OLD only under
   specific short-term circumstances.  Projects should be ported to the NEW
   behavior and not rely on setting a policy to OLD.
+----

-- 

Fun and success!
Mario *LigH* Rohkrämer
mailto:contact at ligh.de