[MIPS][LLDB]Fix TestBreakpointCondition.py for MIPS

Patch by Nitesh Jain

Summary: The self.getArchitecture() returns the architecture based on the value of -A flag passed to dotest.py script.
There are many possible values for MIPS to this option (like mips32r2, mips32r6, mips64, mips64r2,.... ).
This patch uses re.match(mips,arch) to check if architecture string starts with mips.

Subscribers: lldb-commits, mohit.bhakkad, sagar, bhushan, jaydeep
Reviewers: clayborg, ovyalov
Differential: http://reviews.llvm.org/D14493
llvm-svn: 253444