SWDEV-229731 - [Lnx][Rocm][Navi]Support images in full Opencl Conformance tests

1. Enable pitch workaround
2. When we use copy image, we don't need to create the custom pitch image
3. wrtBackImageBuffer_ stores device memory object, not amd image object.

Tests:
conformance kernel read / write test pass with this code change.

Change-Id: I7dca3127adde6ac83e78dd270a2256ebed55c60d

rocclr/device/rocm/rocvirtual.cpp

@@ -366,7 +366,7 @@ bool VirtualGPU::processMemObjects(const amd::Kernel& kernel, const_address para
 
               // If it's not a read only resource, then runtime has to write back
               if (!desc.info_.readOnly_) {
-                wrtBackImageBuffer_.push_back(devCpImg);
+                wrtBackImageBuffer_.push_back(mem->getDeviceMemory(dev()));
                 imageBufferWrtBack_ = true;
               }
             }