GN: Fix gn gen/compile errors for MIPS

third_party/usrsctp/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/crypto.gni")
 
 config("usrsctp_config") {
   include_dirs = [
     "usrsctplib",
     "usrsctplib/netinet",
@@ skipping 104 matching lines @@
       # this way would is incompatible  with windows XP.
       "WINVER=0x0502",
       "_WIN32_WINNT=0x0502",
     ]
   } else {
     defines += [ "NON_WINDOWS_DEFINE" ]
   }
 
   if (is_clang) {
     cflags = [ "-Wno-incompatible-pointer-types" ]
+  } else if (target_cpu == "mipsel") {
+    # mipsel is still using gcc (4.9),
+    # which does not support "-Wno-incompatible-pointer-types"
+    # so let's disable all warnings for this module.
+    cflags = [ "-w" ]
   }
 
   deps = [
     "//crypto:platform",
   ]
 }