sort out the flush_icache_range mess

[Christoph Hellwig]

On Mon, May 11, 2020 at 09:46:17AM +0200, Geert Uytterhoeven wrote:
> Hi Christoph,
> 
> On Sun, May 10, 2020 at 9:55 AM Christoph Hellwig <hch at lst.de> wrote:
> > none of which really are used by a typical MMU enabled kernel, as a.out can
> > only be build for alpha and m68k to start with.
> 
> Quoting myself:
> "I think it's safe to assume no one still runs a.out binaries on m68k."
> http://lore.kernel.org/r/CAMuHMdW+m0Q+j3rsQdMXnrEPm+XB5Y2AQrxW5sD1mZAKgmEqoA@mail.gmail.com

Do you want to drop the:

    select HAVE_AOUT if MMU

for m68k then?

Note that we'll still need flush_icache_user_range for m68k with mmu,
as it also allows binfmt_flat for mmu configs.