Recognize OpenHarmony OS

[Jonathan Schwender]

Hi,

I'm resending my patch from the Feb-19 from my personal account,
since it has come to my attention that our company email servers
don't have DKIM signing enabled, which leads to providers like gmail
dropping emails relayed via mailing-lists.

This patch version also contains a minor correction where in the previous patch
I forgot to add a trailing dash (as in `linux-ohos*-` ) in the
`case $kernel-$os-$obj` statement.

Cheers

Jonathan Schwender