Reuse QAI8 test shapes between GEMM, IGEMM and GEMV

As reference data is cached, it's possible to run larger amounts of
shapes as long as test data is shared.

Signed-off-by: Emil Ohlsson <emil.ohlsson@arm.com>

Approved-by: Felix Johnny Thomasmathibalan <felixjohnny.thomasmathibalan@arm.com>