freedreno/ir3: we can't store immediate values
freedreno/ir3: we can't store immediate values

Fixes some transform-feedback piglits, like:

bin/ext_transform_feedback-nonflat-integral

Signed-off-by: Rob Clark <6f78cdb10adbe0a7fbbf4098125a51f401c77a5f@freedesktop.org>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler