Add INT48 and INT4 datatype support to IDENTITY

Added support to ref model and testing

Signed-off-by: evacha01 <evan.chandler@arm.com>
Change-Id: Iece53d07c8986332fdd8f1ce5ed6265349df1b6a
diff --git a/reference_model/src/ops/op_factory.cc b/reference_model/src/ops/op_factory.cc
index 1891ff4..5dc375d 100644
--- a/reference_model/src/ops/op_factory.cc
+++ b/reference_model/src/ops/op_factory.cc
@@ -569,8 +569,10 @@
             DEF_FACTORY_RANK0_6_ONE_RANK_ONE_TYPE(OpIdentity, BF16);
             DEF_FACTORY_RANK0_6_ONE_RANK_ONE_TYPE(OpIdentity, FP32);
             DEF_FACTORY_RANK0_6_ONE_RANK_ONE_TYPE(OpIdentity, INT32);
+            DEF_FACTORY_RANK0_6_ONE_RANK_ONE_TYPE(OpIdentity, INT4);
             DEF_FACTORY_RANK0_6_ONE_RANK_ONE_TYPE(OpIdentity, INT8);
             DEF_FACTORY_RANK0_6_ONE_RANK_ONE_TYPE(OpIdentity, INT16);
+            DEF_FACTORY_RANK0_6_ONE_RANK_ONE_TYPE(OpIdentity, INT48);
             DEF_FACTORY_RANK0_6_ONE_RANK_ONE_TYPE(OpIdentity, BOOL);
             DEF_FACTORY_RANK0_6_ONE_RANK_ONE_TYPE(OpIdentity, FP64);
             DEF_FACTORY_RANK0_6_ONE_RANK_ONE_TYPE(OpIdentity, FP8E4M3);