COMPMID-433 - Port NEGEMM to support 16 bit fixed point

Change-Id: I82de74d7027bbc8a00a4d6671e968785280d5f6c
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/79498
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Moritz Pflanzer <moritz.pflanzer@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
13 files changed