armTrustedFirmwareTools: include dtc and gcc in nativeBuildInputs to fix darwin build

pkgs/misc/arm-trusted-firmware/default.nix

@@ -2,6 +2,8 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  dtc,
+  gcc,
   openssl,
   pkgsCross,
   buildPackages,
@@ -61,6 +63,10 @@ let
         nativeBuildInputs = [
           pkgsCross.arm-embedded.stdenv.cc # For Cortex-M0 firmware in RK3399
           openssl # For fiptool
+        ]
+        ++ lib.optionals stdenv.hostPlatform.isDarwin [
+          dtc
+          gcc
         ];
 
         # Make the new toolchain guessing (from 2.14+) happy