SYCL: Add fp16 type support to unary op kernels (llama/12788)

* SYCL: Add fp16 support to some elementwise OP kernels

* remove comment

ggml-ci

* Use static_cast directly

* remove not needed cast from tanh

* Use static cast and remove unneeded castings

* Adjust device_support_op for unary OPs

* Use cast_data and typed_data struct to deduplicate casting code

Author: qnixsynapse