IVGCVSW-798 Add Softmax NEON support for QASYMM8

Change-Id: I4f2cca52caf210fdb7d6bb7e9436ac51cb5088b4
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/112398
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
Tested-by: Jenkins <bsgcomp@arm.com>
28 files changed