Allow running without cl_khr_fp16

Change-Id: I0f5396c8f32acc28914e2ff9fe953f977a3077b9
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/93405
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
diff --git a/src/core/CL/cl_kernels/helpers.h b/src/core/CL/cl_kernels/helpers.h
index 4421e74..330d67d 100644
--- a/src/core/CL/cl_kernels/helpers.h
+++ b/src/core/CL/cl_kernels/helpers.h
@@ -24,7 +24,10 @@
 #ifndef ARM_COMPUTE_HELPER_H
 #define ARM_COMPUTE_HELPER_H
 
+#if defined(ARM_COMPUTE_OPENCL_FP16_ENABLED)
 #pragma OPENCL EXTENSION cl_khr_fp16 : enable
+#endif // defined(ARM_COMPUTE_OPENCL_FP16_ENABLED)
+
 #if defined(ARM_COMPUTE_DEBUG_ENABLED)
 #pragma OPENCL EXTENSION cl_arm_printf : enable
 #endif // defined(ARM_COMPUTE_DEBUG_ENABLED)