Merge pull request #4846 from ckhardin/mips-big-endian

Fix to allow a compilation under mips big endian with gcc

src/google/protobuf/stubs/platform_macros.h

@@ -56,7 +56,7 @@
 #elif defined(__aarch64__)
 #define GOOGLE_PROTOBUF_ARCH_AARCH64 1
 #define GOOGLE_PROTOBUF_ARCH_64_BIT 1
-#elif defined(__MIPSEL__)
+#elif defined(__mips__)
 #if defined(__LP64__)
 #define GOOGLE_PROTOBUF_ARCH_MIPS64 1
 #define GOOGLE_PROTOBUF_ARCH_64_BIT 1