Xenial update to 4.4.85 stable release

SRU Justification

    Impact:
       The upstream process for stable tree updates is quite similar
       in scope to the Ubuntu SRU process, e.g., each patch has to
       demonstrably fix a bug, and each patch is vetted by upstream
       by originating either directly from a mainline/stable Linux tree or
       a minimally backported form of that patch. The 4.4.85 upstream stable
       patch set is now available. It should be included in the Ubuntu
       kernel as well.

       git://git.kernel.org/

    TEST CASE: TBD

The following patches from the 4.4.85 stable release shall be applied:
* af_key: do not use GFP_KERNEL in atomic contexts
* dccp: purge write queue in dccp_destroy_sock()
* dccp: defer ccid_hc_tx_delete() at dismantle time
* ipv4: fix NULL dereference in free_fib_info_rcu()
* net_sched/sfq: update hierarchical backlog when drop packet
* ipv4: better IP_MAX_MTU enforcement
* sctp: fully initialize the IPv6 address in sctp_v6_to_addr()
* tipc: fix use-after-free
* ipv6: reset fn->rr_ptr when replacing route
* ipv6: repair fib6 tree in failure case
* tcp: when rearming RTO, if RTO time is in past then fire RTO ASAP
* irda: do not leak initialized list.dev to userspace
* net: sched: fix NULL pointer dereference when action calls some targets
* net_sched: fix order of queue length updates in qdisc_replace()
* mei: me: add broxton pci device ids
* mei: me: add lewisburg device ids
* Input: trackpoint - add new trackpoint firmware ID
* Input: elan_i2c - add ELAN0602 ACPI ID to support Lenovo Yoga310
* ALSA: core: Fix unexpected error at replacing user TLV
* ALSA: hda - Add stereo mic quirk for Lenovo G50-70 (17aa:3978)
* ARCv2: PAE40: Explicitly set MSB counterpart of SLC region ops addresses
* i2c: designware: Fix system suspend
* drm: Release driver tracking before making the object available again
* drm/atomic: If the atomic check fails, return its value first
* drm: rcar-du: lvds: Fix PLL frequency-related configuration
* drm: rcar-du: lvds: Rename PLLEN bit to PLLON
* drm: rcar-du: Fix crash in encoder failure error path
* drm: rcar-du: Fix display timing controller parameter
* drm: rcar-du: Fix H/V sync signal polarity configuration
* tracing: Fix freeing of filter in create_filter() when set_str is false
* cifs: Fix df output for users with quota limits
* cifs: return ENAMETOOLONG for overlong names in cifs_open()/cifs_lookup()
* nfsd: Limit end of page list when decoding NFSv4 WRITE
* perf/core: Fix group {cpu,task} validation
* Bluetooth: hidp: fix possible might sleep error in hidp_session_thread
* Bluetooth: cmtp: fix possible might sleep error in cmtp_session
* Bluetooth: bnep: fix possible might sleep error in bnep_session
* binder: use group leader instead of open thread
* binder: Use wake up hint for synchronous transactions.
* ANDROID: binder: fix proc->tsk check.
* iio: imu: adis16480: Fix acceleration scale factor for adis16480
* iio: hid-sensor-trigger: Fix the race with user space powering up sensors
* staging: rtl8188eu: add RNX-N150NUB support
* ASoC: simple-card: don't fail if sysclk setting is not supported
* ASoC: rsnd: disable SRC.out only when stop timing
* ASoC: rsnd: avoid pointless loop in rsnd_mod_interrupt()
* ASoC: rsnd: Add missing initialization of ADG req_rate
* ASoC: rsnd: ssi: 24bit data needs right-aligned settings
* ASoC: rsnd: don't call update callback if it was NULL
* ntb_transport: fix qp count bug
* ntb_transport: fix bug calculating num_qps_mw
* ACPI: ioapic: Clear on-stack resource before using it
* ACPI / APEI: Add missing synchronize_rcu() on NOTIFY_SCI removal
* Linux 4.4.85