Create custom flags for enabling fp16 support

Resolves: COMPMID-4655

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: I1c1398b39da6da089b288d032074b270d87510c4
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/6010
Reviewed-by: Pablo Marquez Tello <pablo.tello@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/scripts/arm_compute_library_nn_driver.go b/scripts/arm_compute_library_nn_driver.go
index 2461838..689aa3b 100644
--- a/scripts/arm_compute_library_nn_driver.go
+++ b/scripts/arm_compute_library_nn_driver.go
@@ -25,6 +25,7 @@
         theArch := a.ArchType.String()
         if theArch == "armv8-2a" {
           cppflags = append(cppflags, "-march=armv8.2-a+fp16")
+          cppflags = append(cppflags, "-DARM_COMPUTE_ENABLE_FP16")
         }
       }
     }