[arm_gemm] Use static validate to find arm_gemm kernels.

The static method `CpuGemmAssemblyDispatch::validate` should look into
the list of the available kernels to make sure the one requested by
the user was found.

Formatting changes in the files touched by the patch have been
automatically inserted by the formatting script.

Resolves: ONCPUML-840

Change-Id: Icd650a30e142284a942c64f8a2b72441ee7b3f4e
Signed-off-by: Francesco.Petrogalli@arm.com <francesco.petrogalli@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/7375
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Giorgio Arena <giorgio.arena@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/core/NEON/kernels/arm_gemm/gemm_uint16.cpp b/src/core/NEON/kernels/arm_gemm/gemm_uint16.cpp
index d459df8..20cee55 100644
--- a/src/core/NEON/kernels/arm_gemm/gemm_uint16.cpp
+++ b/src/core/NEON/kernels/arm_gemm/gemm_uint16.cpp
@@ -56,6 +56,7 @@
 
 /* Explicitly instantiate the external functions for these types. */
 template UniqueGemmCommon<uint16_t, uint32_t> gemm<uint16_t, uint32_t, Nothing>(const GemmArgs &args, const Nothing &);
+template bool has_opt_gemm<uint16_t, uint32_t, Nothing>(const GemmArgs &args, const Nothing &);
 template std::vector<KernelDescription> get_compatible_kernels<uint16_t, uint32_t, Nothing>(const GemmArgs &args, const Nothing &);
 
 } // namespace arm_gemm