MLBEDSW-1998: Add support for new_axis_mask

-Added support for new_axis_mask
-Added support for more than 1 bit set in new/shrink_axis mask
-Added checks for strided slice in supported operator check
-Added assert if nothing has been put on NPU

Change-Id: I66e2d04784f14d7ad82371f5d649a455d576a818
Signed-off-by: Patrik Gustavsson <patrik.gustavsson@arm.com>
diff --git a/ethosu/vela/supported_operators.py b/ethosu/vela/supported_operators.py
index 1e11d78..1a25887 100644
--- a/ethosu/vela/supported_operators.py
+++ b/ethosu/vela/supported_operators.py
@@ -240,8 +240,14 @@
         return True
 
     def check_memory_only_restrictions(self, op):
-        # check stride size
         if op.type == "StridedSlice":
+            # check stride size
             if len(op.inputs) > 3 and any(stride != 1 for stride in op.inputs[3].values):
                 return False
+            # check ellipsis_mask
+            if op.attrs["ellipsis_mask"] != 0:
+                return False
+            # check if both new_axis_mask and shrink_axis_mask have bit set
+            if op.attrs["new_axis_mask"] != 0 and op.attrs["shrink_axis_mask"] != 0:
+                return False
         return True