Backport ipv6 addrconf.c and dependencies from 3.0.101
Fixes kernel nonstop spamming on ipv6 networks, preventing the device from entering in standby and generating ipv6 traffic affecting phone performance

The dmesg was like this:

<7>[11432.377075,1] p2p0: GOT RA with prefix : rlft 0, vlft 921600,plft 230400, period 0
<7>[11432.377288,1] p2p0: GOT RA with prefix : rlft 0, vlft 921600,plft 230400, period 0
<7>[11432.377441,1] wlan0: GOT RA with prefix : rlft 0, vlft 921600,plft 230400, period 0
<7>[11432.377624,1] wlan0: GOT RA with prefix : rlft 0, vlft 921600,plft 230400, period 0
<7>[11432.379455,1] p2p0: GOT RA with prefix : rlft 0, vlft 921600,plft 230400, period 0
<7>[11432.379577,1] p2p0: GOT RA with prefix : rlft 0, vlft 921600,plft 230400, period 0
<7>[11432.379821,1] wlan0: GOT RA with prefix : rlft 0, vlft 921600,plft 230400, period 0
<7>[11432.380004,1] wlan0: GOT RA with prefix : rlft 0, vlft 921600,plft 230400, period 0
<7>[11432.381622,1] p2p0: RS timer expired.
<7>[11432.381927,1] p2p0: RS timer expired.
<7>[11432.382080,1] wlan0: RS timer expired.
<7>[11432.382202,1] wlan0: RS timer expired.

Change-Id: I03f76a03528e7b12da742c57fa18d0d49f8b08ee
Merge remote-tracking branch 'remotes/CyanogenMod/cm-11.0' into cm-11.0