IVGCVSW-5564 Disable INT16 delegate quant tests on ACL
IVGCVSW-5564 Disable INT16 delegate quant tests on ACL

* Since NEON/CL do not support QSYMM16 for Quantization,
  disabling related tests on both backends and running
  on CpuRef only.

Change-Id: Ifbc44cdfb81f25587ef87af8c44243dd88bb25c3
Signed-off-by: James Conroy <ce41d179dd5a8468f6c1c79fd3299ea93291d455@arm.com>

ARM-software/armnn,ARM-software/armnn,ARM-software/armnn