[mips] Move COP2 & COP3 load/store instructions from MipsInstrFPU.td to MipsInstrInfo.td. NFC.

Reviewers: dsanders

Reviewed By: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5843

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221300 91177308-0d34-0410-b5e6-96231b3b80d8