Add CPU_kernel with float16 for adjust_contrast_op.cc
@cantonios ,

Thanks for the inputs. I got a doubt here. Suppose consider below snippet from identity_op.cc.

https://github.com/tensorflow/tensorflow/blob/9d2607201ed37fef0b3d23249a2f757a9047a680/tensorflow/core/kernels/identity_op.cc#L154-L158

In the above Op code we are using `;` at both Marco end and at Register_Kernel call as well. I am not sure how its not having problem for this case. Any pointers would be appreciated. @cantonios , Done the changes as suggested. Could you please review! > @cantonios ,
> 
> Thanks for the inputs. I got a doubt here. Suppose consider below snippet from identity_op.cc.
> 
> https://github.com/tensorflow/tensorflow/blob/9d2607201ed37fef0b3d23249a2f757a9047a680/tensorflow/core/kernels/identity_op.cc#L154-L158
> 
> In the above Op code we are using `;` at both Marco end and at Register_Kernel call as well. I am not sure how its not having problem for this case. Any pointers would be appreciated.

It does have a problem in that case.  We are likely getting build warnings because of it. Hi @SuryanarayanaY Any update on this PR? Please. Thank you! This PR is stale because it has been open for 14 days with no activity. It will be closed if no further activity occurs. Thank you. Hi @SuryanarayanaY Any update on this PR? Please. Thank you! Hi @SuryanarayanaY Any update on this PR? Please. Thank you! Done the changes. It looks like you still haven't resolved this issue:
```
implicit instantiation of undefined template 'tensorflow::AdjustContrastOpv2
``` Hi @SuryanarayanaY Can you please check @cantonios's comments ? Thank you! Hi @SuryanarayanaY  Any update on this PR? Please. Thank you! Hi @SuryanarayanaY Any update on this PR? Please. Thank you! Hi @SuryanarayanaY Any update on this PR? Please. Thank you! Hi @SuryanarayanaY Any update on this PR? Please. Thank you! Hi @SuryanarayanaY Any update on this PR? Please. Thank you! This PR is stale because it has been open for 14 days with no activity. It will be closed if no further activity occurs. Thank you. Not stale.Looking into it. Updated the kernel. Can you add a test? Hi @SuryanarayanaY Can you please check @cantonios's [comment](https://github.com/tensorflow/tensorflow/pull/61782#issuecomment-1990693272)? Thank you! This PR is stale because it has been open for 14 days with no activity. It will be closed if no further activity occurs. Thank you. This PR was closed because it has been inactive for 14 days since being marked as stale. Please reopen if you'd like to work on this further.
The API `tf.image.adjust_contrast` supports `float16` and `float32` for the argument images . But with `CPU` runtime and `float16` dtype the API raising exception stating there is no kernel available. Refer attached [gist](https://colab.sandbox.google.com/gist/SuryanarayanaY/6990939226d9d79dfe9225b13919c288/61246_cpu.ipynb) for the exception.

Hence adding a kernel for CPU with float16.

Shall also fixes #61246