treewide: cmake buildInputs to nativeBuildInputs, minor cleanups

pkgs/development/libraries/embree/2.x.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchFromGitHub, cmake, pkgconfig, ispc, tbb, glfw,
+{ stdenv, fetchFromGitHub, cmake, pkg-config, ispc, tbb, glfw,
 openimageio, libjpeg, libpng, libpthreadstubs, libX11
 }:
 
@@ -14,11 +14,11 @@ stdenv.mkDerivation {
   };
 
   cmakeFlags = [ "-DEMBREE_TUTORIALS=OFF" ];
-  enableParallelBuilding = true;
-  
-  buildInputs = [ pkgconfig cmake ispc tbb glfw openimageio libjpeg libpng libX11 libpthreadstubs ];
+
+  nativeBuildInputs = [ cmake pkg-config ];
+  buildInputs = [ ispc tbb glfw openimageio libjpeg libpng libX11 libpthreadstubs ];
   meta = with stdenv.lib; {
-    description = "High performance ray tracing kernels from Intel"; 
+    description = "High performance ray tracing kernels from Intel";
     homepage = "https://embree.github.io/";
     maintainers = with maintainers; [ hodapp ];
     license = licenses.asl20;