MIPS: Minor-key-ify new LoadICTrampolineStub.

Port r23409 (31a0d5ae)

BUG=
R=paul.lind@imgtec.com

Review URL: https://codereview.chromium.org/503393002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23423 ce2b1a6d-e550-0410-aec6-3dcde31c8c00