lima/ppir: fix lod bias register codegen

lima/ppir: fix lod bias register codegen

The lod bias register is correctly run through the entire compilation
process, but in the end its allocated register value was never being
added to the instruction.
It seems that most programs were lucky enough that lod bias was assigned
register 0.x so that things worked anyway.

Signed-off-by: Erico Nunes <nunes.erico@gmail.com>
Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4535>