[LLDB][MIPS] Change ARCHFLAG for MIPS

SUMMARY:
    For MIPS, ARCH is specified without m.

    Reviewers: clayborg
    Subscribers: nitesh.jain, mohit.bhakkad, sagar, bhushan and lldb-commits
    Differential Revision: http://reviews.llvm.org/D14978

llvm-svn: 254376

lldb/packages/Python/lldbsuite/test/make/Makefile.rules

@@ -168,6 +168,9 @@ else
 		override ARCH :=
 		override ARCHFLAG :=
 	endif
+	ifeq "$(findstring mips,$(ARCH))" "mips"
+		override ARCHFLAG := -
+	endif
 
 	ifeq "$(SPLIT_DEBUG_SYMBOLS)" "YES"
 		DSYM = $(EXE).debug