m68k/defconfig: Update defconfigs for v4.20-rc1

Actual changes:
    -CONFIG_BATMAN_ADV_DAT=y
    -CONFIG_CRYPTO_SHA512=m
    -CONFIG_NF_CONNTRACK_IPV4=m
    -CONFIG_NF_CONNTRACK_IPV6=m
    +CONFIG_CRC64=m
    +CONFIG_CRYPTO_OFB=m
    +CONFIG_NFT_OSF=m
    +CONFIG_NFT_TPROXY=m
    +CONFIG_NFT_TUNNEL=m
    +CONFIG_NFT_XFRM=m
    +CONFIG_TEST_BITFIELD=m
    +CONFIG_TEST_IDA=m
    +CONFIG_TEST_MEMCAT_P=m
    +CONFIG_TEST_XARRAY=m

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>