dpdk: install files in the standard layout

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

···
   installTargets = [ "install-runtime" "install-sdk" "install-kmod" ]; # skip install-doc
 
   installFlags = [
-    "prefix=$(out)" "datadir=$(out)" "includedir=$(out)/include"
+    "prefix=$(out)"
   ] ++ lib.optionals mod [
     "kerneldir=$(kmod)/lib/modules/${kver}"
   ];

pkgs/os-specific/linux/odp-dpdk/default.nix

···
   nativeBuildInputs = [ autoreconfHook pkgconfig ];
   buildInputs = [ dpdk libconfig libpcap numactl openssl ];
 
-  RTE_SDK = dpdk;
+  RTE_SDK = "${dpdk}/share/dpdk";
   RTE_TARGET = "x86_64-native-linuxapp-gcc";
 
   dontDisableStatic = true;

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

···
     [ dpdk libpcap numactl ]
     ++ stdenv.lib.optionals withGtk [gtk2];
 
-  RTE_SDK = "${dpdk}";
+  RTE_SDK = "${dpdk}/share/dpdk";
   RTE_TARGET = "x86_64-native-linuxapp-gcc";
   GUI = stdenv.lib.optionalString withGtk "true";