Arm backend: Change _is_ok_for_quantization to support output check (#9795)

_is_ok_for_quantization now checks the node itself as well to verify
that the node can be quantized. Previously it was only checked by
looking at the inputs to the node.

This led to TestSplit failing, which is fixed with the change to
`is_non_float_tensor` in `arm_quantizer_utils`, which now handles when
node.meta["val"] is a `list` of `FakeTensor`. It traverses the list and
checks if any of the elements are **not** a `FakeTensor`. If one element
is not a `FakeTensor` the function will return `True`.

Signed-off-by: Sebastian Larsson <sebastian.larsson@arm.com>