musl: Add missing patch hunks from OpenHarmony

The openharmony-linux-user.patch extracted from OpenHarmony only included
modified files, not new files.

With gettid.c being included in musl 1.2.2 we should be able to drop it when
we upgrade to 1.2.2 or later.

Signed-off-by: Esben Haabendal <esben.haabendal@huawei.com>