COMPMID-452 CL Generic Depthwise Convolution implementation.

Change-Id: I115e48fe6ce5e281f3791aa5d80fdc754cdd2b5e
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/85082
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Gian Marco Iodice <gianmarco.iodice@arm.com>
diff --git a/arm_compute/core/CL/OpenCL.h b/arm_compute/core/CL/OpenCL.h
index 562f30b..897e936 100644
--- a/arm_compute/core/CL/OpenCL.h
+++ b/arm_compute/core/CL/OpenCL.h
@@ -82,6 +82,7 @@
     using clReleaseKernel_func           = cl_int (*)(cl_kernel kernel);
     using clGetDeviceInfo_func           = cl_int (*)(cl_device_id, cl_device_info, size_t, void *, size_t *);
     using clGetDeviceIDs_func            = cl_int (*)(cl_platform_id, cl_device_type, cl_uint, cl_device_id *, cl_uint *);
+    using clRetainEvent_func             = cl_int (*)(cl_event);
 
     clBuildProgram_func            clBuildProgram            = nullptr;
     clEnqueueNDRangeKernel_func    clEnqueueNDRangeKernel    = nullptr;
@@ -111,6 +112,7 @@
     clReleaseMemObject_func        clReleaseMemObject        = nullptr;
     clGetDeviceInfo_func           clGetDeviceInfo           = nullptr;
     clGetDeviceIDs_func            clGetDeviceIDs            = nullptr;
+    clRetainEvent_func             clRetainEvent             = nullptr;
 
 private:
     std::pair<bool, bool> _loaded{ false, false };