[MIPS] Fix misspelled macro in t-vxworks

[Mingjie Xing]

Hello,

This patch fix the misspelled macro in t-vxworks.  Is it OK?

2012-05-10  Mingjie Xing  <mingjie.x...@gmail.com>

        * config/mips/t-vxworks: Change MUTLILIB_EXTRA_OPTS to
        MULTILIB_EXTRA_OPTS.

Index: config/mips/t-vxworks
===================================================================
--- config/mips/t-vxworks       (revision 187364)
+++ config/mips/t-vxworks       (working copy)
@@ -32,4 +32,4 @@ MULTILIB_EXCEPTIONS = mips3* mabi=o64 fP
                      $(addprefix mabi=o64/, EL* msoft-float* mrtp* fPIC*) \
                      $(addsuffix /fPIC, *mabi=o64 *mips3 *EL *msoft-float)

-MUTLILIB_EXTRA_OPTS = -G 0 -mno-branch-likely
+MULTILIB_EXTRA_OPTS = -G 0 -mno-branch-likely

Thanks,
Mingjie