[Mips] Does not take in account 'use-soft-float' attribute's value when
consider to generate stubs for mips16 hard-float mode.

The patch reviewed by Reed Kotler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198019 91177308-0d34-0410-b5e6-96231b3b80d8