aco: Allow combining TCS output VMEM stores.

aco: Allow combining TCS output VMEM stores.

Some copypasta may have stuck in the code.
This was left on false by mistake.

Totals (GFX10):
Code Size: 254939248 -> 254896008 (-0.02 %) bytes

Totals from affected shaders (GFX10):
VGPRS: 16196 -> 16212 (0.10 %)
Code Size: 1126332 -> 1083092 (-3.84 %) bytes
Max Waves: 2336 -> 2334 (-0.09 %)

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4165>