Remove 32-bit assumptions from the ELF code.

Change-Id: I2c1f3d34c33685799aade8866eec44479ff9f963
diff --git a/libc/include/link.h b/libc/include/link.h
index 0edf5df..341fbf1 100644
--- a/libc/include/link.h
+++ b/libc/include/link.h
@@ -33,8 +33,7 @@
 
 __BEGIN_DECLS
 
-/* bionic is currently only 32-bit. */
-#define ElfW(type) Elf32_##type
+#define ElfW(type) Elf_##type
 
 struct dl_phdr_info {
   ElfW(Addr) dlpi_addr;