Remove AINT8

- Updated C and Py serialization libraries, updated licence files
- Removed AINT8 from TOSA reference tests

Signed-off-by: Kevin Cheng <kevin.cheng@arm.com>
Signed-off-by: Jared Smolens <jared.smolens@arm.com>
Change-Id: I860bfeaad5a075e50f569c8f6861927ebacf1378