Since movf and movt instructions were removed in r6, sel_s and
sel_d instructions need to be used instead with some preparations.

Change-Id: Ia6a2fda7d3d79ada1ae1ec4649793efd2466f79b
Reviewed-on: https://chromium-review.googlesource.com/1016910Reviewed-by: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Commit-Queue: Sreten Kovacevic <sreten.kovacevic@mips.com>
Cr-Commit-Position: refs/heads/master@{#52683}