freedreno: replace glsl130 debug flag with glsl120

freedreno: replace glsl130 debug flag with glsl120

Now that relative-dst works, we should never fall back to the old
compiler.  (Which is almost true, other than a couple edge case sched
fails in piglit).

So replace glsl130 flag to force GLSL 130 and integers on a3xx/a4xx with
a glsl120 flag to force GLSL 120 and !integers.

If this commit breaks any game/app/etc use FD_MESA_DEBUG=glsl120 as a
workaround and please let me know.

Signed-off-by: Rob Clark <robclark@freedesktop.org>