intel/fs: require memory fence commit bit on Gfx9

Fixes a hang on Gfx9 GT1 : dEQP-VK.compute.zero_initialize_workgroup_memory.max_workgroup_memory.128

Tested-by: Mark Janes <markjanes@swizzler.org>
Acked-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <!15596>