[mips] Remove MipsCC::CCInfo. NFC.

Summary:
It's now passed in as an argument to functions that need it. Eventually
this argument will be replaced by the 'this' pointer for a MipsCCState
object.

Depends on D5966

Reviewers: vmedic

Reviewed By: vmedic

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5967

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221054 91177308-0d34-0410-b5e6-96231b3b80d8