sdrangel: fix darwin build

Tested and changed the platform metadata for the dependent libs.

pkgs/applications/radio/sdrangel/default.nix

···
-{ airspy
+{ lib
+, stdenv
+, airspy
 , airspyhf
 , aptdec
 , boost
···
 , glew
 , hackrf
 , hidapi
-, lib
 , ffmpeg
 , libiio
 , libopus
···
     "-DDAB_LIB=${dab_lib}"
     "-DLIBSERIALDV_INCLUDE_DIR:PATH=${serialdv}/include/serialdv"
     "-DLIMESUITE_INCLUDE_DIR:PATH=${limesuite}/include"
-    "-DLIMESUITE_LIBRARY:FILEPATH=${limesuite}/lib/libLimeSuite.so"
+    "-DLIMESUITE_LIBRARY:FILEPATH=${limesuite}/lib/libLimeSuite${stdenv.hostPlatform.extensions.sharedLibrary}"
     "-DSGP4_DIR=${sgp4}"
     "-DSOAPYSDR_DIR=${soapysdr-with-plugins}"
   ];
···
     homepage = "https://github.com/f4exb/sdrangel";
     license = licenses.gpl3Plus;
     maintainers = with maintainers; [ alkeryn ];
-    platforms = platforms.linux;
+    platforms = platforms.unix;
   };
 }

pkgs/development/libraries/aptdec/default.nix

···
     homepage = "https://github.com/Xerbo/aptdec";
     license = licenses.gpl2;
     maintainers = with maintainers; [ alexwinter ];
-    platforms = platforms.linux;
+    platforms = platforms.unix;
   };
 }

pkgs/development/libraries/cm256cc/default.nix

···
   meta = with lib; {
     description = "Fast GF(256) Cauchy MDS Block Erasure Codec in C++";
     homepage = "https://github.com/f4exb/cm256cc";
-    platforms = platforms.linux;
+    platforms = platforms.unix;
     maintainers = with maintainers; [ alkeryn ];
     license = licenses.gpl3;
   };

pkgs/development/libraries/dab_lib/default.nix

···
     homepage = "https://github.com/JvanKatwijk/dab-cmdline";
     license = licenses.gpl2;
     maintainers = with maintainers; [ alexwinter ];
-    platforms = platforms.linux;
+    platforms = platforms.unix;
   };
 }

pkgs/development/libraries/dsdcc/default.nix

···
     homepage = "https://github.com/f4exb/dsdcc";
     license = licenses.gpl3;
     maintainers = with maintainers; [ alexwinter ];
-    platforms = platforms.linux;
+    platforms = platforms.unix;
   };
 }

pkgs/development/libraries/qt-5/modules/qtspeech.nix

···
-{ qtModule, speechd, pkg-config }:
+{ lib, qtModule, stdenv, speechd, pkg-config }:
 
 qtModule {
   pname = "qtspeech";
   qtInputs = [ ];
-  buildInputs = [ speechd ];
+  buildInputs = lib.optionals stdenv.isLinux [ speechd ];
   nativeBuildInputs = [ pkg-config ];
   outputs = [ "out" "dev" ];
 }

pkgs/development/libraries/serialdv/default.nix

···
   meta = with lib; {
     description = "C++ Minimal interface to encode and decode audio with AMBE3000 based devices in packet mode over a serial link";
     homepage = "https://github.com/f4exb/serialdv";
-    platforms = platforms.linux;
+    platforms = platforms.unix;
     maintainers = with maintainers; [ alkeryn ];
     license = licenses.gpl3;
   };

pkgs/development/libraries/sgp4/default.nix

···
     homepage = "https://github.com/dnwrnr/sgp4";
     license = licenses.asl20;
     maintainers = with maintainers; [ alexwinter ];
-    platforms = platforms.linux;
+    platforms = platforms.unix;
   };
 }