MLBEDSW-2836 Change sets to tuples

Replace conditional checks against sets with tuples.
If not requiring uniqueness, or complex set operations, it is quicker to
use tuples instead.

Signed-off-by: Michael McGeagh <michael.mcgeagh@arm.com>
Change-Id: Ie8732c8d46067244963936c53f0ec81adda50372
diff --git a/ethosu/vela/register_command_stream_util.py b/ethosu/vela/register_command_stream_util.py
index ca7e6bc..ce49fc2 100644
--- a/ethosu/vela/register_command_stream_util.py
+++ b/ethosu/vela/register_command_stream_util.py
@@ -46,7 +46,7 @@
 BASE_PTR_INDEX_MEM2MEM = int((1 << 8) | (3 << 0))
 
 
-UNARY_ELEMWISE_OPS = set((NpuElementWiseOp.ABS, NpuElementWiseOp.LRELU, NpuElementWiseOp.CLZ,))
+UNARY_ELEMWISE_OPS = (NpuElementWiseOp.ABS, NpuElementWiseOp.LRELU, NpuElementWiseOp.CLZ)
 
 
 def to_npu_kernel(kernel: Kernel) -> NpuKernel: