MLBEDSW-4602: Fix Deepspeech scale & bias reuse issue.

 - Deepspeech reuses identical weights and biases throughout
   the network. Since biases are now interleaved with weights
   there is a scaling issue when the ifm scales differ between
   operations using the same weight and scale tensor.

 - This commit uses interleaved weights/scales on their first use
   but separates scales to source memory on subsequent use (if
   the ifm scale is different).

Signed-off-by: Tim Hall <tim.hall@arm.com>
Change-Id: I7aae163438160a919cae04e235966e75355a6148