m68k: defconfig: Update defconfigs for v6.4-rc1

  - Enable modular build of the new DMA pool test,
  - Drop CONFIG_PRINT_QUOTA_WARNING=n (auto-disabled since commit
    36d532d7 ("quota: mark PRINT_QUOTA_WARNING as BROKEN")),
  - Drop CONFIG_UNIX=y and CONFIG_INET=y (implied by 9P_FS since commit
    d7385ba1 ("9p: Remove INET dependency")).

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/5a9bc6058c4fab4b57ba45d778956df8ce7e8688.1683548863.git.geert@linux-m68k.org