rt: merge fixup for v5.4.37 and printk issues

In v5.4.37, upstream ab6f762f ("printk: queue wake_up_klogd
irq_work only if per-CPU areas are ready") was backported.

However, in preempt-rt content we have:

  0011-printk_safe-remove-printk-safe-code.patch
  0025-printk-remove-unused-code.patch

The v5.6-rt already has a backport of ab6f762f present, and has
simply expanded the above removals to account for the backport, so
we do the same thing here for v5.4-rt

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>