Add OHOS macro judgment in the .h file

[SC404]

we are using oneDNN in OpenHarmony, so we would like to add OHOS judgment in the cmakelist and add OHOS macro judgment in the .h file；They suggested that I submit the code to the upstream warehouse here.

[kawakami-k]

@SC404
Thank you for the patch! I'm not familiar with OpenHarmony. Could you give me some explanation about OpenHarmony. Is it one of Linux distributions or an OS derived from Linux? Is the oneDNN community discussing whether oneDNN should support OpenHarmony?

It might be better to prepare a separate header file for OpenHarmony such as util_impl_openharmony.

[vpirogov]

@kawakami-k, we are open to supporting OpenHarmony OS in oneDNN. This patch was initially proposed in uxlfoundation/oneDNN#3703, but it raised questions from Arm and was referred to upstream Xbyak implementation.

[kawakami-k]

@vpirogov
Thank you for the clarification.
@SC404
I agree to modify Xbyak_aarch64 for OpenHarmony. I think the patch requires further consideration. For example, whether it's better to throw an error or set a dummy value.