MLBEDSW-10631: Convert non-constant int4 tensors to int8
Similar as for int48 tensors, we should unpack the constant tensors and change data type for the non-constant ones.
Change-Id: I9c3c69bd2d1e41bfa32e959c35325b1280f626e2 Signed-off-by: Rickard Bolin rickard.bolin@arm.com