[LLDB][MIPS] Getting correct flags for MIPS

Patch by Nitesh Jain

Reviewers: clayborg, ovyalov, emaste.
Subscribers: jaydeep, bhushan, dsanders, mohit.bhakkad, sagar, labath, tberghammer, lldb-commits.
Differential Revision: http://reviews.llvm.org/D10685

llvm-svn: 241045