Comment 1 for bug 1996071

So commit aa127a069ef312aca02b730d5137e1778d0c3ba7 "s390/boot: add secure boot trailer" was just upstream accepted with v6.1-rc3.
And it got tagged for upstream stable with:
"Cc: <email address hidden> # 5.2+"
That means that it will ideally automatically land over time in all Ubuntu kernels, down to focal's 5.4.

But since this bug is marked as critical, the patch is relatively short, traceable and s390x-specific, I'll go ahead and submit this patch for Jammy and Focal ahead of upstream stable.

It's planned to have kernel 6.2 in lunar (23.04), hence it will get the patch automatically when at the planned target level.