[ARM] Pass subtarget feature "+no-movt" instead of passing backend option
"-arm-use-movt=0".
        
This change is needed since backend options do not make it to the backend
when doing LTO and are not capable of changing the behavior of code-gen
passes on a per-function basis.

rdar://problem/21529937

Differential Revision: http://reviews.llvm.org/D11025


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@242368 91177308-0d34-0410-b5e6-96231b3b80d8