Add x86 ELF support

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5258 42af7a65-404d-4744-a932-0658087f49c3

binfmt/libelf/libelf_bind.c

@@ -266,7 +266,9 @@ int elf_bind(FAR struct elf_loadinfo_s *loadinfo,
 
   /* Flush the instruction cache before starting the newly loaded module */
 
+#ifdef CONFIG_ELF_ICACHE
   arch_flushicache((FAR void*)loadinfo->alloc, loadinfo->allocsize);
+#endif
   return ret;
 }