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/misc/my-env/loadenv.sh

@@ -0,0 +1,22 @@
+#!@shell@
+
+OLDPATH="$PATH"
+OLDTZ="$TZ"
+OLD_http_proxy="$http_proxy"
+OLD_ftp_proxy="$http_proxy"
+source @myenvpath@
+
+PATH="$PATH:$OLDPATH"
+export PS1="\n@name@:[\u@\h:\w]\$ "
+export NIX_MYENV_NAME="@name@"
+export buildInputs
+export TZ="$OLDTZ"
+export http_proxy="$OLD_http_proxy"
+export ftp_proxy="$OLD_ftp_proxy"
+
+if test $# -gt 0; then
+    exec "$@"
+else
+    exec @shell@
+fi
+