Update to 6.9.x

Update to 6.9.2 + 6.9-rt5

Note: The latest update 'reverted' to version 6.9.2 as 6.9.3 has the changes from 6.10-rc1 and it's useful to have the version prior to that (second) disruptive change in the Debian archive. See !1081 (comment 497558) for details.

Build issue on arm64 is not resolved after all. For details (and build log), see the comments.

Update: And the maintainer just said that it will be queued up for renesas-ctrl-fixes for v6.10 and that's good enough for me.
It's not yet part of the upstream repo, so I grabbed the patch with b4 and pointed the Origin: header to the ML.

Update 2:
The RT maintainer has added that patch to the RT patch set in v6.10-rc1-rt1, so I 'backported' that and placed it in the debian/patches-rt directory.
If there's another RT update for 6.9.x, then it will likely include that patch.
And it'll likely take a while before the patch/commit lands in Linus' tree and get ready to be picked up for the linux-6.9.y branch.

And with that, I'll remove the Draft status.