These days most of the CPU and GPU used in the SoC of smartphones support some version of OpenCL. In addition, this needs support by the smartphone manufacturer with the right drivers.
The OpenCL Info app can be used to check if the CPU or GPU in your Android device supports OpenCL. It also displays which version of OpenCL is supported and which features of OpenCL are supported.
Tried with: OpenCL Info 1.0.1, Android 4.4.3 and Moto G