Update N800 defconfig, mainly to disable netfilter which
doesn't compile:

    CC      net/ipv4/netfilter/ipt_IDLETIMER.o
net/ipv4/netfilter/ipt_IDLETIMER.c: In function 'utimer_work':
net/ipv4/netfilter/ipt_IDLETIMER.c:80: error: 'struct
net_device' has no member named 'class_dev'
net/ipv4/netfilter/ipt_IDLETIMER.c: In function
'utimer_notifier_call':
net/ipv4/netfilter/ipt_IDLETIMER.c:187: error: 'struct
net_device' has no member named 'class_dev'
net/ipv4/netfilter/ipt_IDLETIMER.c:192: error: 'struct
net_device' has no member named 'class_dev'
net/ipv4/netfilter/ipt_IDLETIMER.c: At top level:
net/ipv4/netfilter/ipt_IDLETIMER.c:276: warning:
initialization from incompatible pointer type
net/ipv4/netfilter/ipt_IDLETIMER.c:277: warning:
initialization from incompatible pointer type
net/ipv4/netfilter/ipt_IDLETIMER.c: In function 'init':
net/ipv4/netfilter/ipt_IDLETIMER.c:290: warning: implicit
declaration of function 'ipt_register_target'
net/ipv4/netfilter/ipt_IDLETIMER.c: In function 'fini':
net/ipv4/netfilter/ipt_IDLETIMER.c:300: warning: implicit
declaration of function 'ipt_unregister_target'

Signed-off-by: Dirk Behme <dirk.behme@gmail.com>