[mips][microMIPS] Fix JRADDIUSP instruction

Fix JRADDIUSP instruction, remove delay slot flag because this instruction
doesn't have delay slot.

Differential Revision: http://reviews.llvm.org/D6365


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222658 91177308-0d34-0410-b5e6-96231b3b80d8