uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

pkgs/os-specific/linux/libwebcam/default.nix

@@ -0,0 +1,51 @@
+{ lib
+, stdenv
+, fetchurl
+, cmake
+, pkg-config
+, libxml2
+}:
+
+stdenv.mkDerivation rec {
+  pname = "libwebcam";
+  version = "0.2.5";
+
+  src = fetchurl {
+    url = "mirror://sourceforge/project/${pname}/source/${pname}-src-${version}.tar.gz";
+    sha256 = "0hcxv8di83fk41zjh0v592qm7c0v37a3m3n3lxavd643gff1k99w";
+  };
+
+  patches = [
+    ./uvcdynctrl_symlink_support_and_take_data_dir_from_env.patch
+  ];
+
+  nativeBuildInputs = [ cmake pkg-config ];
+  buildInputs = [ libxml2 ];
+
+  postPatch = ''
+    substituteInPlace ./uvcdynctrl/CMakeLists.txt \
+      --replace "/lib/udev" "$out/lib/udev"
+
+    substituteInPlace ./uvcdynctrl/udev/scripts/uvcdynctrl \
+      --replace 'debug=0' 'debug=''${NIX_UVCDYNCTRL_UDEV_DEBUG:-0}' \
+      --replace 'uvcdynctrlpath=uvcdynctrl' "uvcdynctrlpath=$out/bin/uvcdynctrl"
+
+    substituteInPlace ./uvcdynctrl/udev/rules/80-uvcdynctrl.rules \
+      --replace "/lib/udev" "$out/lib/udev"
+  '';
+
+
+  preConfigure = ''
+    cmakeFlagsArray=(
+      $cmakeFlagsArray
+      "-DCMAKE_INSTALL_PREFIX=$out"
+    )
+  '';
+
+  meta = with lib; {
+    description = "The webcam-tools package";
+    platforms = platforms.linux;
+    license = licenses.lgpl3;
+    maintainers = with maintainers; [ jraygauthier ];
+  };
+}