arm: Fix fplib 128-bit shift operators
arm: Fix fplib 128-bit shift operators

Appease clang.

pombredanne/http-repo.gem5.org-gem5-,pombredanne/http-repo.gem5.org-gem5-,pombredanne/http-repo.gem5.org-gem5-,pombredanne/http-repo.gem5.org-gem5-,pombredanne/http-repo.gem5.org-gem5-,pombredanne/http-repo.gem5.org-gem5-,pombredanne/http-repo.gem5.org-gem5-