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/networking/mpack/sendmail-via-execvp.diff

@@ -0,0 +1,12 @@
+--- mpack-1.6/unixpk.c	2003-07-21 22:50:41.000000000 +0200
++++ mpack-1.6/unixpk.c	2018-09-16 12:57:14.104026964 +0200
+@@ -254,8 +254,9 @@
+ #ifdef SCO
+     execv("/usr/lib/mail/execmail", addr+start);
+ #else
++    execvp("sendmail", addr+start);
+     execv("/usr/lib/sendmail", addr+start);
+     execv("/usr/sbin/sendmail", addr+start);
+ #endif
+     perror("execv");
+     _exit(1);