Revert "Gold/MIPS: Use EM_MIPS instead of EM_MIPS_RS3_LE for little endian"

This reverts commit 39834263784567c306fbccb8230ddd1badca53fe.  It was
applied unapproved.
diff --git a/gold/configure.tgt b/gold/configure.tgt
index 996bc90..b472b8f 100644
--- a/gold/configure.tgt
+++ b/gold/configure.tgt
@@ -155,7 +155,7 @@
  ;;
 mips*el*-*-*|mips*le*-*-*)
  targ_obj=mips
- targ_machine=EM_MIPS
+ targ_machine=EM_MIPS_RS3_LE
  targ_size=32
  targ_big_endian=false
  targ_extra_big_endian=true