[LLDB][MIPS] Getting correct signals for MIPS Host

Patch by Nitesh Jain

Reviewers: clayborg, ovyalov.
Subscribers: jaydeep, bhushan, dsanders, mohit.bhakkad, sagar, labath, lldb-commits.
Differential Revision: http://reviews.llvm.org/D10180

llvm-svn: 239463