Revert reversion of TensorFlow 2.9 update

With the errors caused by the previous TensorFlow 2.9 update
being fixed, we can proceed with the upgrade.

Signed-off-by: erik.andersson@arm.com <erik.andersson@arm.com>
Change-Id: Ie1f025e8d984efaebc68b8d051126d49bee6b2b8
diff --git a/ethosu/vela/tflite/ArgMaxOptions.py b/ethosu/vela/tflite/ArgMaxOptions.py
index e2f0266..fbf1415 100644
--- a/ethosu/vela/tflite/ArgMaxOptions.py
+++ b/ethosu/vela/tflite/ArgMaxOptions.py
@@ -3,27 +3,17 @@
 # namespace: tflite
 
 import flatbuffers
-from flatbuffers.compat import import_numpy
-np = import_numpy()
 
 class ArgMaxOptions(object):
     __slots__ = ['_tab']
 
     @classmethod
-    def GetRootAs(cls, buf, offset=0):
+    def GetRootAsArgMaxOptions(cls, buf, offset):
         n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, offset)
         x = ArgMaxOptions()
         x.Init(buf, n + offset)
         return x
 
-    @classmethod
-    def GetRootAsArgMaxOptions(cls, buf, offset=0):
-        """This method is deprecated. Please switch to GetRootAs."""
-        return cls.GetRootAs(buf, offset)
-    @classmethod
-    def ArgMaxOptionsBufferHasIdentifier(cls, buf, offset, size_prefixed=False):
-        return flatbuffers.util.BufferHasIdentifier(buf, offset, b"\x54\x46\x4C\x33", size_prefixed=size_prefixed)
-
     # ArgMaxOptions
     def Init(self, buf, pos):
         self._tab = flatbuffers.table.Table(buf, pos)
@@ -35,15 +25,6 @@
             return self._tab.Get(flatbuffers.number_types.Int8Flags, o + self._tab.Pos)
         return 0
 
-def Start(builder): builder.StartObject(1)
-def ArgMaxOptionsStart(builder):
-    """This method is deprecated. Please switch to Start."""
-    return Start(builder)
-def AddOutputType(builder, outputType): builder.PrependInt8Slot(0, outputType, 0)
-def ArgMaxOptionsAddOutputType(builder, outputType):
-    """This method is deprecated. Please switch to AddOutputType."""
-    return AddOutputType(builder, outputType)
-def End(builder): return builder.EndObject()
-def ArgMaxOptionsEnd(builder):
-    """This method is deprecated. Please switch to End."""
-    return End(builder)
\ No newline at end of file
+def ArgMaxOptionsStart(builder): builder.StartObject(1)
+def ArgMaxOptionsAddOutputType(builder, outputType): builder.PrependInt8Slot(0, outputType, 0)
+def ArgMaxOptionsEnd(builder): return builder.EndObject()