[LTP] [PATCH V3] uart: add uart testcase in kernel device-drivers

[Petr Vorel]

Hi Cixi,

thanks for your patch and effort. While we appreciate it, I have to admit that
Cyril's version is IMHO much cleaner and more adjusted to LTP style.

So I'd vote for him to add the loopback and merge his version.

Kind regards,
Petr