nixos/hardware.pcmcia: Fix passthru.function usage

passthru.function is not existent, instead use overrideAttrs which has
almost the intended functionality. It triggers a rebuild, which
_should_ be fine for this package.

(cherry picked from commit e9d9adb)

nixos/modules/hardware/pcmcia.nix

@@ -5,7 +5,7 @@
   ...
 }:
 let
-  pcmciaUtils = pkgs.pcmciaUtils.passthru.function {
+  pcmciaUtils = pkgs.pcmciaUtils.overrideAttrs {
     inherit (config.hardware.pcmcia) firmware config;
   };
 in