COMPMID-1246 Change CLLSTM in order to match android tests

Allow cell to input weights to be nullptr if CIFG and peephole are both enabled.

Change-Id: I6df705d69551f0fddeedd41b2044278d4575469c
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/137902
Tested-by: Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
4 files changed