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/tools/package-management/nix/patches/install-nlohmann_json-headers.patch

@@ -0,0 +1,36 @@
+From 3884f7a69a57d8ecfcbcaae476ec2ff53ffbd549 Mon Sep 17 00:00:00 2001
+From: Robert Hensing <robert@roberthensing.nl>
+Date: Thu, 11 Nov 2021 11:03:21 +0100
+Subject: [PATCH] Install nlohmann_json headers
+
+These headers are included by the libexpr, libfetchers, libstore
+and libutil headers.
+Considering that these are vendored sources, Nix should expose them,
+as it is not a good idea for reverse dependencies to rely on a
+potentially different source that can go out of sync.
+---
+ Makefile              | 1 +
+ src/nlohmann/local.mk | 2 ++
+ 2 files changed, 3 insertions(+)
+ create mode 100644 src/nlohmann/local.mk
+
+diff --git a/Makefile b/Makefile
+index 5040d288485..e6ce50cbdb7 100644
+--- a/Makefile
++++ b/Makefile
+@@ -10,6 +10,7 @@ makefiles = \
+   src/libexpr/local.mk \
+   src/libcmd/local.mk \
+   src/nix/local.mk \
++  src/nlohmann/local.mk \
+   src/resolve-system-dependencies/local.mk \
+   scripts/local.mk \
+   misc/bash/local.mk \
+diff --git a/src/nlohmann/local.mk b/src/nlohmann/local.mk
+new file mode 100644
+index 00000000000..63c427e000e
+--- /dev/null
++++ b/src/nlohmann/local.mk
+@@ -0,0 +1,2 @@
++$(foreach i, $(wildcard src/nlohmann/*.hpp), \
++  $(eval $(call install-file-in, $(i), $(includedir)/nlohmann, 0644)))