Reading JTAG status after writing register/memory makes an extra write

[EvgeniiDidin]

According to Databook we need to check transaction status after memory/register reads and writes by reading JTAG status register. This is made by code added by this commit:
42deccc

But currently this code is not running due incorrect JTAG module behaviour.
For more information how to reproduce incorrect behaviour see STAR 9000833244.

For upstreaming it is not good to add code, which is never running. But we don't want to forget these changes, when fix in HW appears, this commit should be applied.

[EvgeniiDidin]

There is a good code, which checks if JTAG is ready to perform memory/registers r/w. Currently it is disabled, but may be used for debug purposes:
db1bbc7