m68k: defconfig: Update defconfigs for v5.10-rc1

  - Enable modular build of SM2 crypto algorithm,
  - Drop CONFIG_CRYPTO_SM3=m (auto-enabled by CONFIG_CRYPTO_SM2),
  - Drop CONFIG_TEST_BITFIELD=m (converted to KUnit in commit
    d2585f51 ("lib: kunit: add bitfield test conversion to
    KUnit")),
  - Enable modular build of the freeing pages test module.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20201026122549.3092526-1-geert@linux-m68k.org