Fixed issue where cppflags were being set incorrectly

* Build flags were missing -D
   * Changed -ARM_COMPUTE_CPU_ENABLED to -DARM_COMPUTE_CPU_ENABLED
   * Changed -ARM_COMPUTE_OPENCL_ENABLED to -DARM_COMPUTE_OPENCL_ENABLED

Change-Id: I39f996331021e1198f344172ea4ff5a4a360d5ba
Signed-off-by: Pablo Marquez Tello <pablo.tello@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/6510
Reviewed-by: Gunes Bayir <gunes.bayir@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/scripts/arm_compute_library_nn_driver.go b/scripts/arm_compute_library_nn_driver.go
index 689aa3b..cbbe7a7 100644
--- a/scripts/arm_compute_library_nn_driver.go
+++ b/scripts/arm_compute_library_nn_driver.go
@@ -67,8 +67,8 @@
         }
     }
 
-    cppflags = append(cppflags, "-ARM_COMPUTE_CPU_ENABLED")
-    cppflags = append(cppflags, "-ARM_COMPUTE_OPENCL_ENABLED")
+    cppflags = append(cppflags, "-DARM_COMPUTE_CPU_ENABLED")
+    cppflags = append(cppflags, "-DARM_COMPUTE_OPENCL_ENABLED")
 
     return cppflags
 }