Update DTypes for TOSA ops, test rig fixes

- Updated DTypes and expected failures for TOSA ops,
  particularly missing int8/int16 tests for Conv, FullyConnected,
  MatMul
- Fixed a bug where unexpected failures were incorrectly
  categorized as passes

Change-Id: I2763626317cedad9f3723f748986bb59a32f2e42
Signed-off-by: Jared Smolens <jared.smolens@arm.com>