treewide: get rid of osx cmake flags

Flags that we now set globally:

- CMAKE_OSX_SYSROOT
- CMAKE_OSX_DEPLOYMENT_TARGET

can now be removed.

(cherry picked from commit 8742d5de30dfe2447c0fb56a2e7410b402effc80)

pkgs/development/libraries/libui/default.nix

@@ -22,10 +22,6 @@ in
     preConfigure = stdenv.lib.optionalString stdenv.isDarwin ''
       sed -i 's/set(CMAKE_OSX_DEPLOYMENT_TARGET "10.8")//' ./CMakeLists.txt
     '';
-    cmakeFlags = stdenv.lib.optionals stdenv.isDarwin [
-      "-DCMAKE_OSX_SYSROOT="
-      "-DCMAKE_OSX_DEPLOYMENT_TARGET="
-    ];
 
     installPhase = ''
       mkdir -p $out/{include,lib}

pkgs/development/libraries/pcl/default.nix

@@ -29,7 +29,6 @@ stdenv.mkDerivation rec {
 
     ++ stdenv.lib.optionals stdenv.isDarwin [ Cocoa AGL cf-private ];
   cmakeFlags = stdenv.lib.optionals stdenv.isDarwin [
-    "-DCMAKE_OSX_SYSROOT=" "-DCMAKE_OSX_DEPLOYMENT_TARGET="
     "-DOPENGL_INCLUDE_DIR=${OpenGL}/Library/Frameworks"
   ];
 

pkgs/development/libraries/vtk/default.nix

@@ -41,8 +41,6 @@ stdenv.mkDerivation rec {
   cmakeFlags = [ "-DCMAKE_C_FLAGS=-fPIC" "-DCMAKE_CXX_FLAGS=-fPIC" ]
     ++ optional (qtLib != null) [ "-DVTK_USE_QT:BOOL=ON" ]
     ++ optional stdenv.isDarwin [ "-DBUILD_TESTING:BOOL=OFF"
-                                  "-DCMAKE_OSX_SYSROOT="
-                                  "-DCMAKE_OSX_DEPLOYMENT_TARGET="
                                   "-DOPENGL_INCLUDE_DIR=${OpenGL}/Library/Frameworks" ];
 
   postPatch = stdenv.lib.optionalString stdenv.isDarwin ''

pkgs/development/mobile/xpwn/default.nix

@@ -20,10 +20,6 @@ stdenv.mkDerivation {
 
   buildInputs = [ cmake zlib libpng bzip2 libusb openssl ];
 
-  cmakeFlags = [
-    "-DCMAKE_OSX_DEPLOYMENT_TARGET="
-  ];
-
   meta = with stdenv.lib; {
     homepage    = "http://planetbeing.lighthouseapp.com/projects/15246-xpwn";
     description = "Custom NOR firmware loader/IPSW generator for the iPhone";