MLBEDSW-10744: Fix DepthwiseConv2D with batch + depth multiplier

DepthwiseConv2d with batch and depth multiplier is decomposed into
multiple non-batched DepthwiseConv2d followed by Transpose, then a
MemoryCopy to copy the result into the right place in the original
OFM. This last MemoryCopy didn't have the correct IFM shape.

Signed-off-by: Johan Gunnarsson <johan.gunnarsson@arm.com>
Change-Id: I7fe23dbd0bbbb3aca6885153e76a2d3fc8ad7724