MLBEDSW-3774 Remove SplitSliceRead

Removed SplitSliceRead from subgraph during
graph optimisation.

Signed-off-by: Patrik Gustavsson <patrik.gustavsson@arm.com>
Change-Id: I9315d4c2a6767828dd2b4e66823d73b10ebee99c
diff --git a/ethosu/vela/pass_packing.py b/ethosu/vela/pass_packing.py
index b52b159..281c093 100644
--- a/ethosu/vela/pass_packing.py
+++ b/ethosu/vela/pass_packing.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2020 Arm Limited or its affiliates. All rights reserved.
+# Copyright (C) 2020-2021 Arm Limited or its affiliates. All rights reserved.
 #
 # SPDX-License-Identifier: Apache-2.0
 #
@@ -42,8 +42,6 @@
     PostFusingLimited = 8192
 
 
-npu_pre_ops = set((Op.SplitSliceRead,))
-
 mac_main_ops = set(
     (
         # convolutions
@@ -148,16 +146,6 @@
     ),
     (
         # ops_set
-        npu_pre_ops,
-        # incompatible_pack_flags
-        PassFlags.Cpu | PassFlags.MemoryOnly,
-        # flags_to_set
-        PassFlags.Npu | PassFlags.Mac | PassFlags.Pre | PassFlags.ElementWise,
-        # flags_to_clear
-        PassFlags.Empty,
-    ),
-    (
-        # ops_set
         npu_dma_ops,
         # incompatible_pack_flags
         PassFlags.Cpu | PassFlags.MemoryOnly,
@@ -437,7 +425,7 @@
                 visit_op(op, tens)
 
     def create_primary_op(op_list):
-        if any(op.type in (npu_pre_ops | npu_post_ops | npu_post_fuse_limited_ops) and op.run_on_npu for op in op_list):
+        if any(op.type in (npu_post_ops | npu_post_fuse_limited_ops) and op.run_on_npu for op in op_list):
             # Configure a 1x1 AvgPool and attach the op onto it
             op = op_list[0]
             inp = op.inputs[0]