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/build-support/setup-hooks/reproducible-builds.sh

@@ -0,0 +1,10 @@
+# Use the last part of the out path as hash input for the build.
+# This should ensure that it is deterministic across rebuilds of the same
+# derivation and not easily collide with other builds.
+# We also truncate the hash so that it cannot cause reference cycles.
+NIX_CFLAGS_COMPILE="${NIX_CFLAGS_COMPILE:-} -frandom-seed=$(
+    outbase="${out##*/}"
+    randomseed="${outbase:0:10}"
+    echo $randomseed
+)"
+export NIX_CFLAGS_COMPILE