m68k: defconfig: Update defconfigs for v5.7-rc1

  - Enable modular build of Bare UDP Encapsulation, exFAT filesystem
    support, and lockup and min heap test modules,
  - Remove CONFIG_NF_TABLES_SET=m (removed in commit e32a4dc6
    ("netfilter: nf_tables: make sets built-in")),
  - Disable CONFIG_VHOST_MENU (should default to n).

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20200413104153.30517-1-geert@linux-m68k.org