fix CI for OpenOCD/debugger tests

[aap-sc]

git ls-remote lists both refs/head and refs/remotes. riscv-openocd got
a new entry in refs/remotes that matches riscv pattern around Jan 25.
This breaks gitlab pipeline. The commit restricts ls-remote only to
refs/head.

In addition this commit changes the address of riscv-openocd repository,
since it was moved to riscv-collab space a while ago.

[aap-sc]

This PR should fix the issue: #543

[aap-sc]

@lz-bro , @aswaterman FYI.

@en-sc could you please review this one?

[en-sc]

Seems like the other match, which cased trouble (refs/remotes/riscv-openocd/riscv) was added to riscv-openocd by mistake. I have deleted it and the pipelines should work without the patch from now on (re-run example).

However, the link to riscv-openocd repo should still be updated.

As for the part regarding revisions, I do think we can use a more robust mechanism here.
I see the following alternatives:

• Change OPENOCD_REV to HEAD -- this will protect against changing the default branch in riscv-openocd
• Change OPENOCD_REV to refs/tags/latest -- this is the tag, updated by snapshot.yml workflow on push. IMHO, this is the best option, since this tag is the closest thing to a release in riscv-openocd.
• Leave it as-is, since if it works -- don't touch it :)

[aap-sc]

I have deleted it and the pipelines should work without the patch from now on ([re-run example]

Yep. It works now. I'll abandon the patch then