Merge branch '2022-09-14-refactor-ramdisk-code-again' into next

To quote the author:
The previous attempt at this[1] broke a board and was reverted in [2].
This series adopts a slightly different approach, splitting the changes
into many commits.

[1] f33a2c1b ("image: Remove #ifdefs from select_ramdisk()")
[2] 621158d1 ("Revert "image: Remove #ifdefs from select_ramdisk()"")