intel/compiler: Remove INTEL_DEBUG=tcs8

For Gen11 and prior, the dispatch mode for TCS was SINGLE_PATCH, and
this debug setting could be used to change it to 8_PATCH (falling back
to SINGLE_PATCH when shader couldn't be in the multi dispatch mode).
However after talking to Ken, seems this debug setting is not really
worth keeping around, so removing it.

For Gen12+ the only option is 8_PATCH, so it was always using that
dispatch mode as before.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18151>

src/intel/compiler/brw_compiler.c

@@ -116,9 +116,7 @@ brw_compiler_create(void *mem_ctx, const struct intel_device_info *devinfo)
 
    compiler->precise_trig = env_var_as_boolean("INTEL_PRECISE_TRIG", false);
 
-   compiler->use_tcs_8_patch =
-      devinfo->ver >= 12 ||
-      (devinfo->ver >= 9 && INTEL_DEBUG(DEBUG_TCS_EIGHT_PATCH));
+   compiler->use_tcs_8_patch = devinfo->ver >= 12;
 
    /* Default to the sampler since that's what we've done since forever */
    compiler->indirect_ubos_use_sampler = true;