README.md: remove LibDRM dependency - NEO now keeps i915 headers within repo

Change-Id: I6877cee5ae0e2dc0bdee1fad80c1da0cab36f705

Author: PiotrRozenfeld

README.md

@@ -24,7 +24,6 @@ Intel Graphics Compiler - https://github.com/intel/intel-graphics-compiler
 Google Test v1.7.0 - https://github.com/google/googletest  
 Google Mock v1.7.0 - https://github.com/google/googlemock  
 Khronos OpenCL Headers - https://github.com/KhronosGroup/OpenCL-Headers  
-LibDRM - https://anongit.freedesktop.org/git/mesa/drm.git  
 
 ## Supported Platforms