i965: fix MAX_COMPUTE_SHARED_SIZE constant value

MAX_COMPUTE_SHARED_SIZE should be set to 32768. This fixes a regression
introduced in be27f772 (mesa: do not use a constant for
MAX_COMPUTE_SHARED_SIZE).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94139

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/mesa/drivers/dri/i965/brw_context.c

@@ -710,6 +710,7 @@ brw_initialize_cs_context_constants(struct brw_context *brw, unsigned max_thread
    ctx->Const.MaxComputeWorkGroupSize[1] = max_invocations;
    ctx->Const.MaxComputeWorkGroupSize[2] = max_invocations;
    ctx->Const.MaxComputeWorkGroupInvocations = max_invocations;
+   ctx->Const.MaxComputeSharedMemorySize = 32768;
 }
 
 /**