MLBEDSW-8749: MLCE: Output diff on strided slice

 - When possible, a read slice from a split or stride is moved to
the following op. The problem in this case was that the following
op was an elementwise op where the ifm needed to be broadcasted
and that is not supported.
 - The result is a faulty elementwise op with an output diff.
 - The fix is to prevent moving the slice read to the elementwise op
if broadcasting is needed.

Change-Id: I89928c217510a822f91f051fd1ad6e34040c19de
Signed-off-by: Johan Alfven <johan.alfven@arm.com>