a5xx: fix condition for updating *_FS_OUTPUT_CNTL
The register values depend on the currently set program, so make sure to revalidate when the program changes. Fixes glsl-1.10-fragdepth as well as dEQP-GLES3.functional.shaders.fragdepth.compare.* Signed-off-by:Ilia Mirkin <imirkin@alum.mit.edu> Reviewed-by:
Rob Clark <robdclark@gmail.com>