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/busybox/sandbox-shell.nix

@@ -0,0 +1,26 @@
+{ busybox}:
+
+# Minimal shell for use as basic /bin/sh in sandbox builds
+busybox.override {
+  enableStatic = true;
+  enableMinimal = true;
+  extraConfig = ''
+    CONFIG_FEATURE_FANCY_ECHO y
+    CONFIG_FEATURE_SH_MATH y
+    CONFIG_FEATURE_SH_MATH_64 y
+    CONFIG_FEATURE_TEST_64 y
+
+    CONFIG_ASH y
+    CONFIG_ASH_OPTIMIZE_FOR_SIZE y
+
+    CONFIG_ASH_ALIAS y
+    CONFIG_ASH_BASH_COMPAT y
+    CONFIG_ASH_CMDCMD y
+    CONFIG_ASH_ECHO y
+    CONFIG_ASH_GETOPTS y
+    CONFIG_ASH_INTERNAL_GLOB y
+    CONFIG_ASH_JOB_CONTROL y
+    CONFIG_ASH_PRINTF y
+    CONFIG_ASH_TEST y
+  '';
+}