intel/fs: Fix MOV_INDIRECT for 64-bit values on little-core

The same workaround we need for 64-bit values on little core also takes
care of the Ivy Bridge problem and does so a bit more efficiently so we
can drop that code while we're here.

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Cc: mesa-stable@lists.freedesktop.org
(cherry picked from commit fd1bcccc)